CVE-2021-20205Public exploitNetwork attack vector

Process crash via zero-width GIF

Published Mar 10, 2021 · Updated Aug 3, 2024

Divide-by-zero in libjpeg-turbo 2.0.90 and 2.0.91 allows remote attackers to crash cjpeg by supplying a crafted GIF image. The GIF reader in rdgif.c accepts a zero width or height, and start_input_gif passes the invalid dimensions to alloc_sarray, which divides by zero. The target must run cjpeg on the file; the resulting floating-point exception terminates that conversion process without reported data exposure or modification.

CVSS severity6.5
Medium
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Divide-by-zero in libjpeg-turbo 2.0.90 and 2.0.91 allows remote attackers to crash cjpeg by supplying a crafted GIF image. The GIF reader in rdgif.c accepts a zero width or height, and start_input_gif passes the invalid dimensions to alloc_sarray, which divides by zero. The target must run cjpeg on the file; the resulting floating-point exception terminates that conversion process without reported data exposure or modification.

The record

CVE
CVE-2021-20205
Published
Mar 10, 2021
Updated
Aug 3, 2024
Vendor
The libjpeg-turbo Project
Product
libjpeg-turbo
Classifications
CWE-369, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=2.0.90 and 2.0.91

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The libjpeg-turbo Project · libjpeg-turboversion=2.0.90 and 2.0.91

Published CVSS scores

6.5GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
6.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-369Divide By Zero
T1204.002User Execution Malicious File

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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