// For flags

CVE-2025-27773

SimpleSAMLphp SAML2 library has incorrect signature verification for HTTP-Redirect binding

Severity Score

8.6
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
Complete
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
Poc
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-03-06 CVE Reserved
  • 2025-03-11 CVE Published
  • 2025-03-11 CVE Updated
  • 2025-04-12 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-347: Improper Verification of Cryptographic Signature
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Simplesamlphp
Search vendor "Simplesamlphp"
 Saml2
Search vendor "Simplesamlphp" for product "Saml2"
 < 4.17.0
Search vendor "Simplesamlphp" for product "Saml2" and version " < 4.17.0"
en
Affected
Simplesamlphp
Search vendor "Simplesamlphp"
 Saml2
Search vendor "Simplesamlphp" for product "Saml2"
 5.0.0
Search vendor "Simplesamlphp" for product "Saml2" and version "5.0.0"
en
Affected