CVE-2013-2503

CVE-2013-2503 is a medium-severity vulnerability in Privoxy with a CVSS 2.0 base score of 5.8. 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-20.

Key facts

Description

Privoxy before 3.0.21 does not properly handle Proxy-Authenticate and Proxy-Authorization headers in the client-server data stream, which makes it easier for remote HTTP servers to spoof the intended proxy service via a 407 (aka Proxy Authentication Required) HTTP status code.

Frequently asked questions

What is CVE-2013-2503?
Privoxy before 3.0.21 does not properly handle Proxy-Authenticate and Proxy-Authorization headers in the client-server data stream, which makes it easier for remote HTTP servers to spoof the intended proxy service via a 407 (aka Proxy Authentication Required) HTTP status code.
How severe is CVE-2013-2503?
CVE-2013-2503 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2013-2503 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-2503?
CVE-2013-2503 primarily affects Privoxy. In total, 31 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2013-2503?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2013-2503 published?
CVE-2013-2503 was published on 2013-03-11 and last updated on 2026-06-16.

References

Affected products (31)

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