CVE-2013-2503: Privoxy

Medium severity, CVSS 5.8. EPSS: 4.6% chance of exploitation in the next 30 days.

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.

Affected products

• Privoxy Privoxy: up to and including 3.0.20; version 2.9.0 only; version 2.9.1 only; version 2.9.2 only; version 2.9.3 only; version 2.9.11 only; …

Published 2013-03-11. Last modified 2026-06-16.