Vulnerability in Simplesamlphp

CVE-2017-18122

A signature-validation bypass issue was discovered in SimpleSAMLphp through 1.14.16. A SimpleSAMLphp Service Provider using SAML 1.1 will regard as valid any unsigned SAML response containing more than one signed assertion, provided that the signature of at least one of the assertions is valid. Attributes contained in all the assertions received will be merged and the entityID of the first assertion received will be used, allowing an attacker to impersonate any user of any IdP given an assertion signed by the targeted IdP.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2017-18122: held from 0.011 to 0.011.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2017-18122?
CVE-2017-18122 is a high-severity vulnerability in Simplesamlphp, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2018-02-02.
How severe is CVE-2017-18122?
High severity. CVSS v3 base score is 8.1 out of 10.