CVE-2013-4566

mod_nss 1.0.8 and earlier, when NSSVerifyClient is set to none for the server/vhost context, does not enforce the NSSVerifyClient setting in the directory context, which allows remote attackers to bypass intended access restrictions.

Published: 2013-12-12 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2013-4566 is rated Low Risk (25.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.12%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2013-4566

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 2025-03-30 0.26% 0.12% -0.13%
2 2025-03-29 0.13% 0.26% +0.12%
3 2025-03-17 — 0.13% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-4566

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.0 2.0 MEDIUM
AV:N/AC:H/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 4.9 4.9 [email protected]

Weakness enumeration for CVE-2013-4566

OS Trackers for CVE-2013-4566

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2013-4566
ubuntu medium CVE-2013-4566 medium priority: Ubuntu including 1 source packages (libapache2-mod-nss), 30 status rows across 30 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lucid, lunar, mantic, noble, oracular, plucky, precise, quantal, questing, raring, saucy, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): DNE 16, ignored 11, needed 3. https://ubuntu.com/security/CVE-2013-4566

Affected software / configurations for CVE-2013-4566

Vendor Product Version Raw CPE
mod_nss_project mod_nss <= 1.0.8 cpe:2.3:a:mod_nss_project:mod_nss:*:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0 cpe:2.3:a:mod_nss_project:mod_nss:1.0:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.2 cpe:2.3:a:mod_nss_project:mod_nss:1.0.2:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.3 cpe:2.3:a:mod_nss_project:mod_nss:1.0.3:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.4 cpe:2.3:a:mod_nss_project:mod_nss:1.0.4:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.5 cpe:2.3:a:mod_nss_project:mod_nss:1.0.5:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.6 cpe:2.3:a:mod_nss_project:mod_nss:1.0.6:*:*:*:*:*:*:*
mod_nss_project mod_nss 1.0.7 cpe:2.3:a:mod_nss_project:mod_nss:1.0.7:*:*:*:*:*:*:*
redhat enterprise_linux 5 cpe:2.3:o:redhat:enterprise_linux:5:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*

References for CVE-2013-4566

cvelogic Threat Intelligence