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TI-2021-03509 Aliases CVE-2021-20213GHSA-gwg6-gwm3-3g4w

NULL pointer dereference in privoxy

Priority LOW 36CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.

Summary

A flaw was found in Privoxy in versions before 3.0.29. Dereference of a NULL-pointer that could result in a crash if accept-intercepted-requests was enabled, Privoxy failed to get the request destination from the Host header and a memory allocation failed.

Why it matters now

EPSS 0.01571 75th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—privoxyPrivoxy 3.0.29—No fix listedCNA
  • privoxy Vendor— Affected Privoxy 3.0.29 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:privoxy:privoxy:*:*:*:*:*:*:*:*before 3.0.29VulnerablePrivoxy
  • cpe:2.3:a:privoxy:privoxy:*:*:*:*:*:*:*:* Versions before 3.0.29 Vulnerable ·Privoxy

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-20213
  2. 2026-10-03 Alias added: GHSA-gwg6-gwm3-3g4w

References

Patch 1

Advisory 2

  • TI-2016-01816 The client_host function in parsers.c in Privoxy before 3.0.24 allows remote attackers to… CVSS 3.0HIGH 7.5
  • TI-2016-01815 The remove_chunked_transfer_coding function in filters.c in Privoxy before 3.0.24 allows… CVSS 3.0HIGH 7.5
  • TI-2021-03567 Memory corruption in privoxy CVSS 3.1HIGH 7.5
  • TI-2021-03566 Memory corruption in privoxy CVSS 3.1HIGH 7.5
  • TI-2021-03565 NULL pointer dereference in privoxy CVSS 3.1HIGH 7.5
  • TI-2021-03564 Improper input validation in privoxy CVSS 3.1HIGH 7.5
See all 28 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences