ruby-saml

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system.

This vulnerability was reported by ahacker1 of SecureSAML (ahacker1@securesaml.com)

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system.

This vulnerability was reported by ahacker1 of SecureSAML (ahacker1@securesaml.com)

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system.

This vulnerability was reported by ahacker1 of SecureSAML (ahacker1@securesaml.com)

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.

Ruby-saml uses zlib to decompress SAML responses in case they're compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.

Impact

This issue may lead to remote Denial of Service (DoS).

Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system.

This vulnerability was reported by ahacker1 of SecureSAML (ahacker1@securesaml.com)

xml_security.rb in the ruby-saml gem before 1.0.0 for Ruby allows XPath injection and code execution because prepared statements are not used.

OneLogin Ruby-SAML 1.6.0 and earlier may incorrectly utilize the results of XML DOM traversal and canonicalization APIs in such a way that an attacker may be able to manipulate the SAML data without invalidating the cryptographic signature, allowing the attack to potentially bypass authentication to SAML service providers.

ruby-saml prior to version 1.3.0 is vulnerable to an XML signature wrapping attack in the specific scenario where there was a signature that referenced at the same time 2 elements (but past the scheme validator process since 1 of the element was inside the encrypted assertion). ruby-saml users must update to 1.3.0, which implements 3 extra validations to mitigate this kind of attack.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Details

When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded.

Impact

1. Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly.

2. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication.

Summary

Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.

Impact

That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication

Summary

A denial-of-service vulnerability exists in ruby-saml even with the message_max_bytesize setting configured. The vulnerability occurs because the SAML response is validated for Base64 format prior to checking the message size, leading to potential resource exhaustion.

Details

ruby-saml includes a message_max_bytesize setting intended to prevent DOS attacks and decompression bombs. However, this protection is ineffective in some cases due to the order of operations in the code:

https://github.com/SAML-Toolkits/ruby-saml/blob/fbbedc978300deb9355a8e505849666974ef2e67/lib/onelogin/ruby-saml/saml_message.rb

      def decode_raw_saml(saml, settings = nil)
        return saml unless base64_encoded?(saml) # <--- Issue here. Should be moved after next code block.

        settings = OneLogin::RubySaml::Settings.new if settings.nil?
        if saml.bytesize > settings.message_max_bytesize
          raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
        end

        decoded = decode(saml)
        ...
      end

The vulnerability is in the execution order. Prior to checking bytesize the base64_encoded? function performs regex matching on the entire input string:

!!string.gsub(/[\r\n]|\\r|\\n|\s/, "").match(BASE64_FORMAT)

Impact

What kind of vulnerability is it? Who is impacted?

When successfully exploited, this vulnerability can lead to:

• Excessive memory consumption
• High CPU utilization
• Application slowdown or unresponsiveness
• Complete application crash in severe cases
• Potential denial of service for legitimate users

All applications using ruby-saml with SAML configured and enabled are vulnerable.

Potential Solution

Reorder the validation steps to ensure max bytesize is checked first

def decode_raw_saml(saml, settings = nil)
  settings = OneLogin::RubySaml::Settings.new if settings.nil?

  if saml.bytesize > settings.message_max_bytesize
    raise ValidationError.new("Encoded SAML Message exceeds " + settings.message_max_bytesize.to_s + " bytes, so was rejected")
  end
  
  return saml unless base64_encoded?(saml)
  decoded = decode(saml)
  ...
end

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.