CVE-2011-4362

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 21.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2011-12-24 · updated 2026-06-16

Description

Integer signedness error in the base64_decode function in the HTTP authentication functionality (http_auth.c) in lighttpd 1.4 before 1.4.30 and 1.5 before SVN revision 2806 allows remote attackers to cause a denial of service (segmentation fault) via crafted base64 input that triggers an out-of-bounds read with a negative index.

Affected products

Debian Linux: 5.0, 6.0, 7.0
lighttpd: from 1.4.1 before 1.4.30; 1.5.0 — fixed in 1.4.30

How to fix

Upgrade to a fixed version: lighttpd 1.4.30. Check the vendor advisory for mitigations.

References

http://archives.neohapsis.com/archives/bugtraq/2011-12/0167.html
http://blog.pi3.com.pl/?p=277
http://download.lighttpd.net/lighttpd/security/lighttpd_sa_2011_01.txt
http://jvn.jp/en/jp/JVN37417423/index.html
http://redmine.lighttpd.net/issues/2370
http://secunia.com/advisories/47260
http://www.debian.org/security/2011/dsa-2368
http://www.exploit-db.com/exploits/18295
http://www.openwall.com/lists/oss-security/2011/11/29/13
http://www.openwall.com/lists/oss-security/2011/11/29/8
http://www.securitytracker.com/id?1026359
https://bugzilla.redhat.com/show_bug.cgi?id=758624

Get alerted when CVE-2011-4362 or the next vulnerability affects your stack