Which products and versions are affected by CVE-2009-0478?

Affected: Squid versions 2.7.stable1, 2.7.stable2, 2.7.stable3, 2.7.stable4, 2.7.stable5, 3.0.stable1, 3.0.stable10, 3.0.stable11; squid3 (debian). The full list is in the CVE brief.

Is CVE-2009-0478 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-2009-0478 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-2009-0478?

Public exploit code is available.

Is there a fix for CVE-2009-0478?

Fixed versions are available, including Squid 2.7.STABLE3-4.1, squid3 3.0.PRE5-5+etch1.

How urgently should CVE-2009-0478 be patched?

Brandefense priority: patch immediately, because it is very likely to be exploited soon.

Request A Demo

Vulnerability Intelligence

CVE-2009-0478

MediumPublic exploit

Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a denial of service via an HTTP request with an invalid version number, which triggers a reachable assertion in (1) HttpMsg.c and (2) HttpStatusLine.c.

Published Feb 8, 2009 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2009-0478, DSA-1732-1

Key Facts

Patch immediately

CVE-2009-0478 is a medium-severity vulnerability (CVSS 5.0 v2) affecting Squid, squid3 (debian).
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 72% probability of exploitation in the next 30 days.
Fixed versions are available, including Squid 2.7.STABLE3-4.1, squid3 3.0.PRE5-5+etch1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

CVSS v2

5.0

AV:N/AC:L/Au:N/C:N/I:N/A:P

EPSS (30-day exploit likelihood)

72%

Higher than 99.4% of all scored CVEs

Exploited in the wild

No known

Not in a known-exploited catalog

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2009-0478 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Affected Products

34 affected entries in total

Product	Affected versions	Fixed in
SquidSquid	2.7.stable1, 2.7.stable2, 2.7.stable3, 2.7.stable4, 2.7.stable5, 3.0.stable1, 3.0.stable10, 3.0.stable11	2.7.STABLE3-4.1
squid3debian	See advisory	3.0.PRE5-5+etch1

Patched Releases

Squid

2.7.STABLE3-4.1

squid3

3.0.PRE5-5+etch1

Timeline

Publicly disclosed
Feb 8, 2009
Last updated
Aug 4, 2026

Weakness Type

CWE-20 Improper Input Validation

References

advisory33731
advisory34467
advisoryhttps://security-tracker.debian.org/tracker/CVE-2009-0478
advisoryhttp://www.squid-cache.org/Advisories/SQUID-2009_1.txt
advisoryhttp://www.squid-cache.org/Versions/v2/2.7/changesets/12432.patch

8 more references in the full CVE brief

FAQ

Common Questions.

Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a denial of service via an HTTP request with an invalid version number, which triggers a reachable assertion in (1) HttpMsg.c and (2) HttpStatusLine.c.
Affected: Squid versions 2.7.stable1, 2.7.stable2, 2.7.stable3, 2.7.stable4, 2.7.stable5, 3.0.stable1, 3.0.stable10, 3.0.stable11; squid3 (debian). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Squid 2.7.STABLE3-4.1, squid3 3.0.PRE5-5+etch1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.

Is CVE-2009-0478 Running On Your Attack Surface?

Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.