CVE-2020-5214
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 · uneditedIn NetHack before 3.6.5, detecting an unknown configuration file option can cause a buffer overflow resulting in a crash or remote code execution/privilege escalation. This vulnerability affects systems that have NetHack installed suid/sgid and shared systems that allow users to upload their own configuration files. Users should upgrade to NetHack 3.6.5.
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 confidenceA buffer overflow vulnerability in NetHack versions before 3.6.5 exists in the configuration file parsing code. When the program detects an unknown configuration file option, it fails to properly handle the input, causing a buffer overflow that can lead to crash or arbitrary code execution with elevated privileges.
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< 3.6.5CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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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Identify installed NetHack versionRun `nethack --version` or check via package manager (dpkg -l nethack, rpm -q nethack, etc.) or inspect the binary for embedded version stringsAffected if Version displayed is before 3.6.5 (such as 3.6.4 or earlier)
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Locate NetHack configuration filesCheck for user or system configuration files: ~/.nethackrc, ~/.config/nethack/, /etc/nethackrc, or paths specified via NETHACKOPTIONS environment variableAffected if Custom or non-default configuration files exist and are loaded by NetHack
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Determine if custom config options are parsedReview any active configuration files for custom options or examine if NetHack processes options from files beyond defaultsAffected if Configuration files contain user-defined or non-standard options that could trigger unknown option handling
Environment is affected if installed NetHack version is below 3.6.5 and the application processes user-provided configuration files containing custom options.
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.
dbcve · scoped3.6.5
Upgrade to NetHack 3.6.5 or later. Remove suid/sgid bits from NetHack installations on shared systems and restrict user-provided configuration files.
NetHack 3.6.5
- Check current NetHack version using 'nethack --version' or similar command
- Download NetHack 3.6.5 from the official source (github.com/nethack/nethack)
- Back up any existing NetHack configuration files if needed
- Install NetHack 3.6.5 using the appropriate method for your system (package manager, compile from source, or binary)
- If previously using custom configuration files, review them for any unknown options that may have caused the overflow
- Verify the new version is installed correctly by running 'nethack --version'
- If installed suid/sgid, ensure proper permissions are set after upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5214 — 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-2020-5214 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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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.
- 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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