Security readout for executives and security teams
Plain-English summary
SimpleSAMLphp could accept a manipulated SAML 1.1 login response as valid when multiple signed assertions were present. For exposed service providers, this could let an attacker impersonate users if they already had an assertion signed by the targeted identity provider.
Executive priority
Prioritize remediation for identity-facing applications because successful abuse could become account impersonation. Urgency is highest where SimpleSAMLphp is internet-facing, legacy SAML 1.1 is enabled, or privileged applications rely on it.
Technical view
In SimpleSAMLphp through 1.14.16, SAML 1.1 service providers could validate an unsigned response containing multiple signed assertions if at least one assertion had a valid signature. Attributes from all assertions were merged and the first assertion entityID was used, enabling user impersonation across the targeted IdP context.
Likely exposure
Exposure is most likely in legacy SimpleSAMLphp service provider deployments that still support SAML 1.1 and run version 1.14.16 or earlier. Deployments using only newer protocol handling or updated packages are less likely to be affected.
Exploitation context
The bundle does not cite active exploitation, and the CVE is not listed as KEV. Exploitation requires a vulnerable SAML 1.1 SP flow and an assertion signed by the targeted identity provider, making impact serious but context-dependent.
Researcher notes
The key condition is not general SAML signature failure; it is response validation with multiple signed assertions under SAML 1.1. Evidence in the bundle does not provide CVSS, CWE, exploit-in-the-wild status, or full fixed version details beyond the affected range.
Mitigation direction
- Upgrade SimpleSAMLphp according to the SimpleSAMLphp security advisory.
- Apply relevant Debian security updates where SimpleSAMLphp is installed from Debian packages.
- Review whether SAML 1.1 support is still required in service provider configurations.
- Follow vendor guidance if local packaging or deployment differs from Debian.
Validation and detection
- Inventory SimpleSAMLphp versions and flag deployments through 1.14.16.
- Identify service provider configurations that accept SAML 1.1 responses.
- Confirm Debian hosts have the DSA-4127 or DLA-1273-1 fixed packages applied.
- Review authentication logs for unusual cross-IdP or unexpected attribute combinations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2017-18122 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- [debian-lts-announce] 20180209 [SECURITY] [DLA 1273-1] simplesamlphp security updateCVE reference · mailing-list, x_refsource_MLIST
- DSA-4127CVE reference · vendor-advisory, x_refsource_DEBIAN
- https://simplesamlphp.org/security/201710-01CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.