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PrivoxyApplication

CVE-2016-1983

HIGH · 7.5 CVSS v3.0 Published 2016-01-27
Fix available
A fix is available. Upgrade to after 3.0.23 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The client_host function in parsers.c in Privoxy before 3.0.24 allows remote attackers to cause a denial of service (invalid read and crash) via an empty HTTP Host header.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Privoxy before 3.0.24 contains a vulnerability in the client_host function in parsers.c where an empty HTTP Host header triggers an invalid read leading to a crash. This occurs because the parsing logic does not properly handle the case where the Host header is present but empty, causing a denial of service.

MitigationUpgrade Privoxy to version 3.0.24 or later, which contains the fix for proper handling of empty HTTP Host headers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PrivoxyApplication
Affected:<= 3.0.23

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Privoxy version
    Run 'privoxy --version' or check your installed package version using your system's package manager (dpkg, rpm, brew, etc.)
    Affected if The reported version is 3.0.23 or lower
  2. Confirm Privoxy is running
    Check if the Privoxy service or process is active (ps aux | grep privoxy, systemctl status privoxy, or similar)
    Affected if Privoxy is running and configured to handle HTTP proxy requests
  3. Verify HTTP proxy functionality
    Confirm Privoxy is configured to accept HTTP connections (check config files for listen-address or port settings)
    Affected if Privoxy is accessible and processing HTTP requests

You are affected if Privoxy version 3.0.23 or earlier is installed and the service is running to process HTTP requests with Host headers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 3.0.23
Interim mitigation

Upgrade Privoxy to version 3.0.24 or later, which contains the fix for proper handling of empty HTTP Host headers.

Fix this in Privoxy Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-1983 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data