CVE-2020-35502
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 · uneditedA flaw was found in Privoxy in versions before 3.0.29. Memory leaks when a response is buffered and the buffer limit is reached or Privoxy is running out of memory can lead to a system crash.
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 confidencePrivoxy before version 3.0.29 contains a memory leak vulnerability in its response buffering mechanism. When the buffer limit is reached or the system is running low on memory, the leak triggers and can cause a system crash due to memory exhaustion, resulting in denial of service.
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< 3.0.29CVSS 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:3.1/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 checksWork through these to decide whether this CVE applies to you.
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Verify Privoxy is installedRun 'which privoxy' or check for the binary in common paths like /usr/sbin/privoxy or /usr/local/sbin/privoxyAffected if Privoxy binary is not found on the system - not affected if absent
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Determine installed Privoxy versionRun 'privoxy --version' or 'privoxy -v' to display version information. On some systems, check the package manager: 'dpkg -l privoxy' (Debian/Ubuntu) or 'rpm -qi privoxy' (RHEL/CentOS)Affected if Version number displayed is lower than 3.0.29 - vulnerable
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Confirm Privoxy service is runningRun 'systemctl status privoxy' or 'service privoxy status' depending on your init system. Alternatively, check for the process: 'ps aux | grep privoxy'Affected if Service is running and version is below 3.0.29 - vulnerable and potentially exploitable
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Check response buffering is in useReview Privoxy configuration file (typically at /etc/privoxy/config or /etc/privoxy/config) for buffer-related directives such as 'buffering' or 'max-buffers'. If using default configuration, buffering is typically enabled by defaultAffected if Buffering feature is enabled and version is below 3.0.29 - vulnerable to memory exhaustion
If Privoxy is installed with a version lower than 3.0.29 and the service is running with response buffering enabled, the environment is affected by CVE-2020-35502 and may be vulnerable to denial of service via memory exhaustion.
Generated from the published advisory. Verify against your own configuration.
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 data3.0.29
Upgrade Privoxy to version 3.0.29 or later to obtain the patched version that addresses the memory leak in the buffering code.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-35502 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-35502 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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