CVE-2018-7711: Debian Linux

High severity, CVSS 8.1. EPSS: 1.2% chance of exploitation in the next 30 days.

HTTPRedirect.php in the saml2 library in SimpleSAMLphp before 1.15.4 has an incorrect check of return values in the signature validation utilities, allowing an attacker to get invalid signatures accepted as valid by forcing an error during validation. This occurs because of a dependency on PHP functionality that interprets a -1 error code as a true boolean value.

Affected products

• Debian Debian Linux: version 7.0 only
• Simplesamlphp SAML2: from 1.0.0, before 1.10.6 (fixed in 1.10.6); from 2.0.0, before 2.3.8 (fixed in 2.3.8); from 3.0.0, before 3.1.4 (fixed in 3.1.4)
• Simplesamlphp Simplesamlphp: before 1.15.4 (fixed in 1.15.4)

Published 2018-03-05. Last modified 2026-06-17.