CVE-2023-36661

Shibboleth XMLTooling before 3.2.4, as used in OpenSAML and Shibboleth Service Provider, allows SSRF via a crafted KeyInfo element. (This is fixed in, for example, Shibboleth Service Provider 3.4.1.3 on Windows.)

Published: 2023-06-25 Last update: 2025-05-05 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-36661 is rated Moderate Risk (63.9/100): CVSS High severity, with high exploitation likelihood (EPSS 60.67%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: 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-2023-36661

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 2026-01-30 61.19% 60.67% -0.52%
2 2026-01-18 60.67% 61.19% +0.52%
3 2025-11-21 60.67%

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-36661

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-36661

OS Trackers for CVE-2023-36661

vendor priority summary link
debian not yet assigned CVE-2023-36661 not yet assigned priority: Debian including 1 source packages (xmltooling), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-36661
redhat medium https://access.redhat.com/security/cve/CVE-2023-36661
suse medium CVE-2023-36661 severity moderate: SUSE including 16 source package names (libshibsp-lite6, libshibsp-lite7, …), 176 product×package rows across 40 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7, … (40 product lines)): Known Not Affected 110, Fixed 66. https://www.suse.com/security/cve/CVE-2023-36661/
ubuntu medium CVE-2023-36661 medium priority: Ubuntu including 1 source packages (xmltooling), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needed 4, ignored 3, not-affected 3, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2023-36661

Affected software / configurations for CVE-2023-36661

Vendor Product Version Raw CPE
shibboleth xmltooling < 3.2.4 cpe:2.3:a:shibboleth:xmltooling:*:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*

References for CVE-2023-36661

cvelogic Threat Intelligence