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CVE-2016-9814 Simplesamlphp CVE debrief

CVE-2016-9814 is a critical authentication flaw in SimpleSAMLphp and the simplesamlphp/saml2 library. The issue is in validateSignature, where improper conversion of return values to boolean can let a remote attacker spoof SAML responses and may also trigger denial of service through memory consumption.

Vendor
Simplesamlphp
Product
CVE-2016-9814
CVSS
CRITICAL 9.1
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-17
Original CVE updated
2026-05-13
Advisory published
2017-02-17
Advisory updated
2026-05-13

Who should care

Organizations that use SimpleSAMLphp or the simplesamlphp/saml2 library for SAML authentication, especially environments relying on federated login, single sign-on, or identity provider integrations.

Technical summary

The vulnerability affects SimpleSAMLphp before 1.14.10 and simplesamlphp/saml2 before 1.9.1, 1.10.x before 1.10.3, and 2.x before 2.3.3. NVD classifies the weakness as CWE-399 and rates the issue CVSS 3.0 9.1 (network reachable, no privileges required, no user interaction), with high integrity and availability impact. The core problem is incorrect boolean handling in signature validation, which can undermine SAML response trust decisions.

Defensive priority

Immediate. This is a remote, unauthenticated authentication-integrity issue with critical severity and possible availability impact.

Recommended defensive actions

  • Upgrade SimpleSAMLphp to 1.14.10 or later.
  • Upgrade simplesamlphp/saml2 to 1.9.1, 1.10.3, 2.3.3, or a newer fixed release that is not affected.
  • Verify SAML deployments that depend on these libraries, including bundled or transitive copies, and confirm the upgraded version is actually in use at runtime.
  • Review authentication logs and SSO integration behavior for unexpected SAML response acceptance or unusual memory growth, especially around signature validation paths.
  • Track vendor and downstream advisories for environment-specific remediation guidance.

Evidence notes

The CVE description and NVD record identify the flaw in validateSignature and describe the spoofing and memory-consumption impact. The affected-version ranges come from the CVE text, NVD CPE criteria, and the linked SimpleSAMLphp vendor advisory. No KEV entry is present in the supplied enrichment data.

Official resources

Publicly disclosed in the CVE record on 2017-02-17, with vendor and NVD references available in the supplied corpus.