CVE-2013-4559

lighttpd before 1.4.33 does not check the return value of the (1) setuid, (2) setgid, or (3) setgroups functions, which might cause lighttpd to run as root if it is restarted and allows remote attackers to gain privileges, as demonstrated by multiple calls to the clone function that cause setuid to fail when the user process limit is reached.

Published: 2013-11-20 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2013-4559 is rated Moderate Risk (64.9/100): CVSS High severity, with high exploitation likelihood (EPSS 10.72%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +1.20% over the last day, indicating growing attacker interest. 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-2013-4559

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 2026-06-15 9.52% 10.72% +1.20%
2 2026-04-11 13.98% 9.52% -4.46%
3 2026-03-04 13.98%

Full EPSS history (45 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-4559

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.6 2.0 HIGH
AV:N/AC:H/Au:N/C:C/I:C/A:C 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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
4.9 10.0 [email protected]

Weakness enumeration for CVE-2013-4559

OS Trackers for CVE-2013-4559

vendor priority summary link
alpine CVE-2013-4559: 1 source package rows (lighttpd); 5 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 5. https://security.alpinelinux.org/vuln/CVE-2013-4559
debian not yet assigned CVE-2013-4559 not yet assigned priority: Debian including 1 source packages (lighttpd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2013-4559
gentoo high CVE-2013-4559: 1 GLSA(s) (201406-10), 1 atom(s) (www-servers/lighttpd); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-4559
ubuntu medium CVE-2013-4559 medium priority: Ubuntu including 1 source packages (lighttpd), 13 status rows across 13 suites (lucid, precise, quantal, raring, saucy, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): not-affected 7, ignored 5, pending 1. https://ubuntu.com/security/CVE-2013-4559

Affected software / configurations for CVE-2013-4559

Vendor Product Version Raw CPE
lighttpd lighttpd < 1.4.33 cpe:2.3:a:lighttpd:lighttpd:*:*:*:*:*:*:*:*
debian debian_linux 6.0 cpe:2.3:o:debian:debian_linux:6.0:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
opensuse opensuse 12.2 cpe:2.3:o:opensuse:opensuse:12.2:*:*:*:*:*:*:*
opensuse opensuse 12.3 cpe:2.3:o:opensuse:opensuse:12.3:*:*:*:*:*:*:*
opensuse opensuse 13.1 cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*

References for CVE-2013-4559

cvelogic Threat Intelligence