Description
The strListGetItem function in src/HttpHeaderTools.c in Squid 2.7 allows remote attackers to cause a denial of service via a crafted auth header with certain comma delimiters that trigger an infinite loop of calls to the strcspn function.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | squid | 2.7.STABLE7-1 | — |
| Debian 13 | squid | 2.7.STABLE7-1 | — |
| Debian 12 | squid | 2.7.STABLE7-1 | — |
| Debian 5.0 | squid | 2.7.STABLE3-4.1lenny1 | DSA-1991-1 |
| Debian 5.0 | squid3 | 3.0.STABLE8-3+lenny3 | DSA-1991-1 |
| Debian 4.0 | squid | 2.6.5-6etch5 | DSA-1991-1 |
| Debian 4.0 | squid3 | 3.0.PRE5-5+etch2 | DSA-1991-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | squid | 7:2.6.STABLE21-6.el5 | RHSA-2010:0221 |
Advisories 2
- RHSA-2010:0221 Red Hat Security Advisory: squid security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1991-1 squid squid3 - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
References
- [oss-security] 20090803 Re: squid DoS in external auth header parser mailing-list
- 36091 vdb-entry
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=534982
- [oss-security] 20090804 Re: squid DoS in external auth header parser mailing-list
- http://www.squid-cache.org/bugs/show_bug.cgi?id=2704
- http://www.squid-cache.org/bugs/show_bug.cgi?id=2541
- 1022757 vdb-entry
- oval:org.mitre.oval:def:10592 vdb-entry signature
- https://bugzilla.redhat.com/show_bug.cgi?id=518182
- [oss-security] 20090720 squid DoS in external auth header parser mailing-list
- squid-strlistgetitem-dos(52610) vdb-entry
- http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=31%3Bfilename=diff%3Batt=1%3Bbug=534982