CVE-2009-0478

CVE-2009-0478 is a medium-severity vulnerability in Squid with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 72% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Description

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.

Frequently asked questions

What is CVE-2009-0478?
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.
How severe is CVE-2009-0478?
CVE-2009-0478 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-0478 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 72% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0478?
CVE-2009-0478 primarily affects Squid. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0478?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0478 published?
CVE-2009-0478 was published on 2009-02-08 and last updated on 2026-06-16.

References

Affected products (22)

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