CVE-2017-18122
A signature-validation bypass issue was discovered in SimpleSAMLphp through 1.14.16.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.0
- 8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.09% probability · 65th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- simplesamlphp/simplesamlphp · debian/debian linux
- Source
- cve@mitre.org
EPSS 1.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://lists.debian.org/debian-lts-announce/2018/02/msg00008.htmlMailing List, Third Party Advisory
- https://simplesamlphp.org/security/201710-01Patch, Vendor Advisory
- https://www.debian.org/security/2018/dsa-4127Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/02/msg00008.htmlMailing List, Third Party Advisory
- https://simplesamlphp.org/security/201710-01Patch, Vendor Advisory
- https://www.debian.org/security/2018/dsa-4127Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.