CVE-2024-45409 | The Ruby SAML library vulnerable to a SAML authentication bypass via Incorrect XPath selector

The Ruby SAML library is for implementing the client side of a SAML authorization. Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system. This vulnerability is fixed in 1.17.0 and 1.12.3.

Published: 2024-09-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-45409 is rated High Risk (76.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 44.64%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.22% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-45409

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-23 42.42% 44.64% +2.22%
2 2026-04-10 40.66% 42.42% +1.77%
3 2026-03-04 — 40.66% —

Full EPSS history (52 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-45409

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 5.8 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2024-45409

GitHub Security Advisory for CVE-2024-45409

GHSA-jw9c-mfg7-9rx2 · Severity: critical · Ecosystem: rubygems — SAML authentication bypass via Incorrect XPath selector

OS Trackers for CVE-2024-45409

vendor priority summary link
debian not yet assigned CVE-2024-45409 not yet assigned priority: Debian including 1 source packages (ruby-saml), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2024-45409
ubuntu medium CVE-2024-45409 medium priority: Ubuntu including 1 source packages (ruby-saml), 7 status rows across 7 suites (bionic, focal, jammy, noble, oracular, upstream, xenial): released 7. https://ubuntu.com/security/CVE-2024-45409

Affected software / configurations for CVE-2024-45409

Vendor Product Version Raw CPE
onelogin ruby-saml < 1.12.3 cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*
onelogin ruby-saml >= 1.13.0, < 1.17.0 cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*
omniauth omniauth_saml <= 1.10.3 cpe:2.3:a:omniauth:omniauth_saml:*:*:*:*:*:ruby:*:*
omniauth omniauth_saml 2.0.0 cpe:2.3:a:omniauth:omniauth_saml:2.0.0:*:*:*:*:ruby:*:*
omniauth omniauth_saml 2.1.0 cpe:2.3:a:omniauth:omniauth_saml:2.1.0:*:*:*:*:ruby:*:*
gitlab gitlab < 16.11.10 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab >= 17.0.0, < 17.0.8 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab >= 17.1.0, < 17.1.8 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab >= 17.2.0, < 17.2.7 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*
gitlab gitlab >= 17.3.0, < 17.3.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:*:*:*:*

References for CVE-2024-45409

cvelogic Threat Intelligence