CVE-2025-25291CWE-347CWE-436

ruby-saml vulnerable to SAML authentication bypass due to DOCTYPE handling (parser differential)

Critical · published March 12, 2025

CVSS v4.0
9.3
EPSS
21%
Percentile
97.6
In the wild
Unconfirmed
What it is

🔥 An authentication bypass vulnerability in ruby-saml means attackers could potentially skip right past your security measures! Think of it like a restaurant where two different chefs interpret the same recipe differently. One might end up with a delicious dish, while the other serves something completely off — the diner’s experience changes based on which chef they get! This authentication bypass could allow attackers to impersonate legitimate users, gaining unauthorized access to sensitive systems and data. This could lead to data breaches, identity theft, or worse, wreaking havoc on your applications and the users who trust them.

Put simply

Think of it like a restaurant where two different chefs interpret the same recipe differently. One might end up with a delicious dish, while the other serves something completely off — the diner’s experience changes based on which chef they get! The vulnerability arises due to a parser differential between ReXML and Nokogiri, leading to different document structures from the same XML input. This allows a Signature Wrapping attack to bypass authentication mechanisms in ruby-saml before versions 1.12.4 and 1.18.0.

What to do

This authentication bypass could allow attackers to impersonate legitimate users, gaining unauthorized access to sensitive systems and data. This could lead to data breaches, identity theft, or worse, wreaking havoc on your applications and the users who trust them. Update ruby-saml to version 1.12.4 or 1.18.0 immediately to patch this vulnerability. Ensure that all instances using the affected versions are audited and updated to secure your applications. You've got this! With these steps, you can keep your systems safe and sound! 🛡️

The record
Technical detail
CVSS v4.0
9.3 · CRITICAL
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.20965 · 97.6th percentile
Weaknesses
CWE-347 · Improper Verification of Cryptographic Signature; CWE-436 · Interpretation Conflict
Published
2025-03-12T20:16Z
EPSS history
Timeline
  • 12 MAR 20:16Z
    ruby-saml vulnerable to SAML authentication bypass due to DOCTYPE handling (parser differential)
    cvelistv5