CVE-2013-2503

NONECVSS 0.0Weaponized
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 5%CVSS: —Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
—
EG Score
0.0(none)
EPSS
90.6%
KEV
Not listed

Published

March 11, 2013

Last Modified

April 29, 2026

References (6)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 35× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 02:19 UTCEPSS rescore
  2. 2026-07-06 02:19 UTCEPSS rescore
  3. 2026-07-05 09:29 UTCOSV refresh
  4. 2026-07-05 02:26 UTCEPSS rescore
  5. 2026-07-04 06:27 UTCEPSS rescore
  6. 2026-07-01 15:02 UTCEPSS rescore
  7. 2026-06-30 23:19 UTCEPSS rescore
  8. 2026-06-30 23:19 UTCEPSS rescore
  9. 2026-06-29 14:02 UTCEPSS rescore
  10. 2026-06-28 14:03 UTCEPSS rescore
  11. 2026-06-28 04:53 UTCEPSS rescore
  12. 2026-06-28 04:53 UTCEPSS rescore
  13. 2026-06-27 03:05 UTCEPSS rescore
  14. 2026-06-25 13:46 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-24 14:02 UTCEPSS rescore
  17. 2026-06-23 21:30 UTCEPSS rescore
  18. 2026-06-21 14:53 UTCEPSS rescore
  19. 2026-06-21 01:57 UTCEPSS rescore
  20. 2026-06-21 01:56 UTCEPSS rescore
  21. 2026-06-19 19:23 UTCEPSS rescore
  22. 2026-06-19 19:22 UTCEPSS rescore
  23. 2026-06-18 17:49 UTCEPSS rescore
  24. 2026-06-18 17:49 UTCEPSS rescore
  25. 2026-06-17 17:49 UTCEPSS rescore
Show 48 more
  1. 2026-06-17 17:49 UTCEPSS rescore
  2. 2026-06-16 20:35 UTCOSV refresh
  3. 2026-06-16 17:49 UTCEPSS rescore
  4. 2026-06-16 17:49 UTCEPSS rescore
  5. 2026-06-15 17:44 UTCEPSS rescore
  6. 2026-06-14 23:14 UTCEPSS rescore
  7. 2026-06-13 22:57 UTCEPSS rescore
  8. 2026-06-12 23:08 UTCEPSS rescore
  9. 2026-06-11 13:56 UTCEPSS rescore
  10. 2026-06-10 13:18 UTCEPSS rescore
  11. 2026-06-07 15:22 UTCEPSS rescore
  12. 2026-06-06 13:45 UTCEPSS rescore
  13. 2026-06-06 13:45 UTCEPSS rescore
  14. 2026-06-05 22:44 UTCEPSS rescore
  15. 2026-06-05 22:44 UTCEPSS rescore
  16. 2026-06-05 06:08 UTCEPSS rescore
  17. 2026-06-05 06:08 UTCEPSS rescore
  18. 2026-06-02 20:10 UTCEPSS rescore
  19. 2026-06-02 20:10 UTCEPSS rescore
  20. 2026-05-31 22:28 UTCEPSS rescore
  21. 2026-05-31 22:28 UTCEPSS rescore
  22. 2026-05-31 00:14 UTCEPSS rescore
  23. 2026-05-31 00:14 UTCEPSS rescore
  24. 2026-05-29 13:41 UTCEPSS rescore
  25. 2026-05-29 13:41 UTCEPSS rescore
  26. 2026-05-29 00:41 UTCEG score recompute
  27. 2026-05-29 00:41 UTCGHSA enrichment
  28. 2026-05-28 13:42 UTCEPSS rescore
  29. 2026-05-28 13:42 UTCEPSS rescore
  30. 2026-05-28 13:42 UTCEPSS rescore
  31. 2026-05-27 13:38 UTCEPSS rescore
  32. 2026-05-27 13:38 UTCEPSS rescore
  33. 2026-05-26 13:41 UTCEPSS rescore
  34. 2026-05-26 13:41 UTCEPSS rescore
  35. 2026-05-26 07:16 UTCEPSS rescore
  36. 2026-05-26 07:16 UTCEPSS rescore
  37. 2026-05-24 16:43 UTCEPSS rescore
  38. 2026-05-22 21:15 UTCEPSS rescore
  39. 2026-05-22 21:15 UTCEPSS rescore
  40. 2026-05-22 21:15 UTCEPSS rescore
  41. 2026-05-21 22:39 UTCEPSS rescore
  42. 2026-05-20 22:37 UTCEPSS rescore
  43. 2026-05-20 22:37 UTCEPSS rescore
  44. 2026-05-20 11:21 UTCEPSS rescore
  45. 2026-05-20 11:21 UTCEPSS rescore
  46. 2026-05-20 11:21 UTCEPSS rescore
  47. 2026-05-18 21:29 UTCEPSS rescore
  48. 2026-05-18 21:29 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-38377✓ verified
    First seen Mar 11, 2013

    Privoxy Proxy - Authentication Information Disclosure

    Open source ↗

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2013-2503?
CVE-2013-2503 is a none vulnerability published on March 11, 2013. 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.
When was CVE-2013-2503 disclosed?
CVE-2013-2503 was first published in the National Vulnerability Database on March 11, 2013, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2013-2503 actively exploited?
CVE-2013-2503 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 90.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2013-2503?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2013-2503, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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