CVE-2020-23922Public exploit

Heap data disclosure via out-of-bounds color-map read

Published Apr 21, 2021 · Updated Aug 4, 2024

Out-of-bounds read in gif2rgb in Giflib 5.1.4 and earlier allows local users to expose heap data or crash the utility via malformed GIF input. DumpScreen2RGB reads a color-map byte immediately beyond a 48-byte heap allocation at gif2rgb.c line 294 while converting the crafted image. Exploitation requires a user to run gif2rgb on the malformed file; the demonstrated result is process termination, while adjacent heap bytes can influence converted output.

CVSS severity7.1
High
EPSS probability2.24%
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 gif2rgb in Giflib 5.1.4 and earlier allows local users to expose heap data or crash the utility via malformed GIF input. DumpScreen2RGB reads a color-map byte immediately beyond a 48-byte heap allocation at gif2rgb.c line 294 while converting the crafted image. Exploitation requires a user to run gif2rgb on the malformed file; the demonstrated result is process termination, while adjacent heap bytes can influence converted output.

The record

CVE
CVE-2020-23922
Published
Apr 21, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-126, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 21, 2021CVE 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.1NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
5.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:N/A:P

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-126Buffer Over-read
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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