CVE-2020-5253: nethack Incomplete List of Disallowed Inputs
CVSS: 9.8v3.1CriticalModified
AliasesUBUNTU-CVE-2020-5253DEBIAN-CVE-2020-5253openSUSE-SU-2025:14898-1
Published 10-03-2020Last modified 04-08-2024
Vulnerability summary
CVE-2020-5253 is a critical (CVSS 9.8) Incomplete List of Disallowed Inputs vulnerability in nethack. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.3% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
0.54%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-03-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
NetHack before version 3.6.0 allowed malicious use of escaping of characters in the configuration file (usually .nethackrc) which could be exploited. This bug is patched in NetHack 3.6.0.
CVSS metrics
5 scores · 4 sources · 2 versionsCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSources4 sources · 3.9–9.8
- CVE.orgCNA3.9LowCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
0.54%
Chance of exploitation in the next 30 days
Percentile
44%
Versus all other CVEs
30-day change
0.00 pp
From 0.54% on 18-09-2026
18-09-202618-10-2026
EPSS score0.54%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-184Incomplete List of Disallowed InputsThe product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.
- CWE-269Improper Privilege ManagementThe product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
Affected systems
Debian1 product
- nethack< 3.6.0-1
Nethack1 product
- nethack< 3.6.0
Opensuse1 product
- nethack&distro=openSUSE Tumbleweed< 3.4.3-6.1
Ubuntu1 product
- nethackAll versions (No fix recorded)
4 vendors · 4 products
References
8 links- github.com/NetHack/NetHack/security/advisories/GHSA-2c7p-3fj4-223mX Refsource CONFIRMREPORTThird Party Advisory
- github.com/NetHack/NetHack/commits/612755bfb5c412079795c68ba392df5d93874ed8X Refsource MISCREPORTPatchThird Party Advisory
- lists.opensuse.org/archives/…Advisory