CVE-2020-5254Public exploit

Privilege escalation via invalid highlight color

Published Mar 10, 2020 · Updated Aug 4, 2024

Out-of-bounds read in NetHack 3.6.1 through 3.6.5 allows local users to escalate privileges through a crafted configuration file. The hilite_status parser fails to reject an invalid status-highlight color before the value is used, allowing memory corruption. Exploitation requires a suid/sgid installation or a shared system that accepts user-supplied configuration files, where the corruption can cross a privilege boundary.

CVSS severity3.9
Low
EPSS probability1.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in NetHack 3.6.1 through 3.6.5 allows local users to escalate privileges through a crafted configuration file. The hilite_status parser fails to reject an invalid status-highlight color before the value is used, allowing memory corruption. Exploitation requires a suid/sgid installation or a shared system that accepts user-supplied configuration files, where the corruption can cross a privilege boundary.

The record

CVE
CVE-2020-5254
Published
Mar 10, 2020
Updated
Aug 4, 2024
Vendor
NetHack
Product
NetHack
Classifications
CWE-119, CWE-125, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 10, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.6.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

NetHack · NetHackversion=< 3.6.6

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
3.9GitHub, Inc.CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-125Out-of-bounds Read
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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