How severe is CVE-2018-7711?

CVE-2018-7711 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-7711 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-7711?

CVE-2018-7711 primarily affects Simplesamlphp. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-7711?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2018-7711 published?

CVE-2018-7711 was published on 2018-03-05 and last updated on 2026-06-17.

CVE-2018-7711

CVE-2018-7711 is a high-severity vulnerability in Simplesamlphp with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Simplesamlphp
Published: 2018-03-05
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2018-7711?: 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 severe is CVE-2018-7711?: CVE-2018-7711 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-7711 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-7711?: CVE-2018-7711 primarily affects Simplesamlphp. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-7711?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-7711 published?: CVE-2018-7711 was published on 2018-03-05 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:simplesamlphp:simplesamlphp:*:*:*:*:*:*:*:*
cpe:2.3:a:simplesamlphp:saml2:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*

More vulnerabilities in Simplesamlphp

CVE-2018-6521 — Critical (CVSS 9.8): The sqlauth module in SimpleSAMLphp before 1.15.2 relies on the MySQL utf8 charset, which truncates queries upon…
CVE-2017-12873 — Critical (CVSS 9.8): SimpleSAMLphp 1.7.0 through 1.14.10 might allow attackers to obtain sensitive information, gain unauthorized access, or…
CVE-2017-12868 — Critical (CVSS 9.8): The secureCompare method in lib/SimpleSAML/Utils/Crypto.php in SimpleSAMLphp 1.14.13 and earlier, when used with PHP…
CVE-2016-9814 — Critical (CVSS 9.1): The validateSignature method in the SAML2\Utils class in SimpleSAMLphp before 1.14.10 and simplesamlphp/saml2 library…
CVE-2019-3465 — High (CVSS 8.8): Rob Richards XmlSecLibs, all versions prior to v3.0.3, as used for example by SimpleSAMLphp, performed incorrect…
CVE-2017-18122 — High (CVSS 8.1): A signature-validation bypass issue was discovered in SimpleSAMLphp through 1.14.16. A SimpleSAMLphp Service Provider…

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