CVE-2018-7711
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 65% of all known CVEs.
References
Related Vulnerabilities
Other CWE-347 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2018-16042 | Medium | 6.5 | 82% | - | - |
| CVE-2025-25292 | Critical | 9.8 | 65% | - | Fix |
| CVE-2025-59718 | Critical | 9.8 | 63% | KEV | Fix |
| CVE-2021-22160 | Critical | 9.8 | 53% | - | Fix |
| CVE-2013-3900 | Medium | 5.5 | 45% | KEV | - |
| CVE-2018-0114 | High | 7.5 | 43% | - | Fix |
Common questions
How do I fix CVE-2018-7711?
Upgrade simplesamlphp on debian 11 to 1.15.4-1 or later.
Is CVE-2018-7711 being actively exploited?
Not that we know of. CVE-2018-7711 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 65% of all scored CVEs.
How severe is CVE-2018-7711?
CVE-2018-7711 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2018-7711 affect?
Published advisories record a fix for simplesamlphp (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.