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NethackApplication

CVE-2023-24809

MEDIUM · 5.5 CVSS v3.1 Published 2023-02-17
Fix available
A fix is available. Upgrade to 3.6.7 or later.
See remediation →
57/100
Remediation priority · Elevated
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
NetHack is a single player dungeon exploration game. Starting with version 3.6.2 and prior to version 3.6.7, illegal input to the "C" (call) command can cause a buffer overflow and crash the NetHack process. This vulnerability may be a security issue for systems that have NetHack installed suid/sgid and for shared systems. For all systems, it may result in a process crash. This issue is resolved in NetHack 3.6.7. There are no known workarounds.

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

The 'C' (call) command in NetHack versions 3.6.2 through 3.6.6 accepts illegal input that triggers a buffer overflow, causing the process to crash. On systems where NetHack is installed with suid/sgid privileges, this could potentially be exploited for privilege escalation.

MitigationUpgrade to NetHack version 3.6.7 or later. No workarounds exist. For suid/sgid installations, prioritize this patch given the potential for local privilege escalation.

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
NethackApplication
Affected:>= 3.6.2, < 3.6.7

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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. Determine installed NetHack version
    Run 'nethack --version' or 'nethack -version' to see the version number. Alternatively, check the banner displayed when starting NetHack, or look for version information in the binary using 'strings' on the executable.
    Affected if The installed version is 3.6.2, 3.6.3, 3.6.4, 3.6.5, or 3.6.6.
  2. Locate the NetHack executable and its permissions
    Find the NetHack binary using 'which nethack' or 'find /usr -name nethack -type f 2>/dev/null'. Then check file permissions with 'ls -la <path_to_nethack>' to see if the setuid or setgid bits are set (indicated by 's' in the owner/group execute fields).
    Affected if The binary has the setuid (suid) or setgid (sgid) bit set, increasing the potential impact of exploitation.
  3. Verify the 'C' (call) command is accessible in-game
    Start NetHack and type 'C' at the prompt to access the call menu, or review the game documentation/options to confirm the call command feature is enabled by default. The vulnerability triggers when this command accepts specially crafted input.
    Affected if The 'C' command is functional and accepts user input, which is the default behavior in affected versions.

You are affected if NetHack version 3.6.2 through 3.6.6 is installed and the 'C' command is accessible; the presence of suid/sgid permissions on the binary significantly elevates the risk.

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.

dbcve · scoped
Upgrade available Upgrade to 3.6.7 or later
Fixed in 3.6.7
Interim mitigation

Upgrade to NetHack version 3.6.7 or later. No workarounds exist. For suid/sgid installations, prioritize this patch given the potential for local privilege escalation.

Recommended fix High confidence

NetHack 3.6.7

  1. Identify the currently installed NetHack version using 'nethack --version' or checking the package manager
  2. Download NetHack 3.6.7 from the official source (nethack.org or GitHub releases)
  3. Backup any custom configurations, save files, or level data if applicable
  4. Install NetHack 3.6.7 following the platform-specific installation instructions
  5. Verify the installation by running 'nethack --version' and confirming it shows version 3.6.7
  6. If NetHack was previously installed with suid/sgid permissions, reapply the appropriate permissions after upgrade (e.g., chmod u+s or chmod g+s)
Caveat Review the NetHack 3.6.7 release notes for any gameplay changes or configuration differences before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Nethack Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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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-2023-24809 in production — separate from our analysis above.

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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