How severe is CVE-2009-0801?

CVE-2009-0801 has a CVSS 2.0 base score of 5.4, rated medium severity.

Is CVE-2009-0801 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0801?

CVE-2009-0801 primarily affects Squid Squid Web Proxy Cache. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0801?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-0801 published?

CVE-2009-0801 was published on 2009-03-04 and last updated on 2026-06-16.

CVE-2009-0801

CVE-2009-0801 is a medium-severity vulnerability in Squid Squid Web Proxy Cache with a CVSS 2.0 base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-264.

Key facts

Severity: Medium (CVSS 2.0 base score 5.4)
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-264
Affected product: Squid Squid Web Proxy Cache
Published: 2009-03-04
Last modified: 2026-06-16

Description

Squid, when transparent interception mode is enabled, uses the HTTP Host header to determine the remote endpoint, which allows remote attackers to bypass access controls for Flash, Java, Silverlight, and probably other technologies, and possibly communicate with restricted intranet sites, via a crafted web page that causes a client to send HTTP requests with a modified Host header.

Frequently asked questions

What is CVE-2009-0801?: Squid, when transparent interception mode is enabled, uses the HTTP Host header to determine the remote endpoint, which allows remote attackers to bypass access controls for Flash, Java, Silverlight, and probably other technologies, and possibly communicate with restricted intranet sites, via a crafted web page that causes a client to send HTTP requests with a modified Host header.
How severe is CVE-2009-0801?: CVE-2009-0801 has a CVSS 2.0 base score of 5.4, rated medium severity.
Is CVE-2009-0801 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0801?: CVE-2009-0801 primarily affects Squid Squid Web Proxy Cache. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0801?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0801 published?: CVE-2009-0801 was published on 2009-03-04 and last updated on 2026-06-16.

References

Affected products (16)

cpe:2.3:a:squid:squid_web_proxy_cache:2.7:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:2.7.stable5:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:2.7.stable6:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_pre1:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_pre2:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_pre3:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable1:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable2:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable3:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable4:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable5:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable6:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable7:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable12:*:*:*:*:*:*:*
cpe:2.3:a:squid:squid_web_proxy_cache:3.0_stable13:*:*:*:*:*:*:*

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