CVE-2023-24809 | NetHack Call command buffer overflow

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.

Published: 2023-02-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-24809 is rated Low Risk (27.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-24809

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.24% +0.18%
2 2025-12-14 0.04% 0.06% +0.01%
3 2025-03-30 0.04%

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-24809

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2023-24809

OS Trackers for CVE-2023-24809

vendor priority summary link
alpine medium CVE-2023-24809: 1 source package rows (nethack); 9 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 3. https://security.alpinelinux.org/vuln/CVE-2023-24809
debian not yet assigned CVE-2023-24809 not yet assigned priority: Debian including 1 source packages (nethack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2023-24809
ubuntu medium CVE-2023-24809 medium priority: Ubuntu including 1 source packages (nethack), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 6. https://ubuntu.com/security/CVE-2023-24809

Affected software / configurations for CVE-2023-24809

Vendor Product Version Raw CPE
nethack nethack >= 3.6.2, < 3.6.7 cpe:2.3:a:nethack:nethack:*:*:*:*:*:*:*:*

References for CVE-2023-24809

cvelogic Threat Intelligence