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.
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.
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)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.6 | 2.0 | HIGH |
|
4.9 | 10.0 | [email protected] |
| 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 |
| 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:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://download.lighttpd.net/lighttpd/security/lighttpd_sa_2013_02.txt | Vendor Advisory |
| http://jvn.jp/en/jp/JVN37417423/index.html | Third Party Advisory |
| http://lists.opensuse.org/opensuse-updates/2014-01/msg00049.html | Mailing List Third Party Advisory |
| http://marc.info/?l=bugtraq&m=141576815022399&w=2 | Issue Tracking Third Party Advisory |
| http://secunia.com/advisories/55682 | Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2013/11/12/4 | Mailing List Third Party Advisory |
| https://kc.mcafee.com/corporate/index?page=content&id=SB10310 | Third Party Advisory |
| https://www.debian.org/security/2013/dsa-2795 | Third Party Advisory |