Description
Squid 2.5 STABLE9 and earlier, when the DNS client port is unfiltered and the environment does not prevent IP spoofing, allows remote attackers to spoof DNS lookups.
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 | 2.5.9-9 | — |
| Debian 13 | squid | 2.5.9-9 | — |
| Debian 12 | squid | 2.5.9-9 | — |
| Debian 3.0 | squid | 2.4.6-2woody9 | DSA-751-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 4 | squid | 7:2.5.STABLE6-3.4E.9 | RHSA-2005:415 |
| RHEL 3 | squid | 7:2.5.STABLE3-6.3E.13 | RHSA-2005:415 |
Advisories 2
- RHSA-2005:415 Red Hat Security Advisory: squid security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-751-1 squid - IP spoofing Debian Security (DSA / DLA) · Mar 9, 2026
References
- 13592 vdb-entry
- oval:org.mitre.oval:def:9976 vdb-entry signature
- FEDORA-2005-373 vendor-advisory
- 15294 third-party-advisory
- FLSA-2006:152809 vendor-advisory
- DSA-751 vendor-advisory
- RHSA-2005:489 vendor-advisory
- ADV-2005-0521 vdb-entry
- http://www.squid-cache.org/Versions/v2/2.5/bugs/#squid-2.5.STABLE9-dns_query