CVE-2021-32491Public exploit

Application crash via unchecked render buffer sizing

Published Jun 24, 2021 · Updated Aug 3, 2024

Integer overflow in DjVuLibre 3.5.28 and earlier allows context-dependent attackers to crash ddjvu with a crafted DjVu file. The render() function in tools/ddjvu.cpp multiplies rowsize by the render-rectangle height without a size_t overflow check, allocates the wrapped size, and later passes an oversized length to fwrite. Processing the malicious document is required; the demonstrated consequence is a heap-buffer over-read followed by application abort, while broader effects are unspecified.

CVSS severity7.8
High
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in DjVuLibre 3.5.28 and earlier allows context-dependent attackers to crash ddjvu with a crafted DjVu file. The render() function in tools/ddjvu.cpp multiplies rowsize by the render-rectangle height without a size_t overflow check, allocates the wrapped size, and later passes an oversized length to fwrite. Processing the malicious document is required; the demonstrated consequence is a heap-buffer over-read followed by application abort, while broader effects are unspecified.

The record

CVE
CVE-2021-32491
Published
Jun 24, 2021
Updated
Aug 3, 2024
Vendor
DjVuLibre Project
Product
DjVuLibre
Classifications
CWE-190, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 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=djvulibre-3.5.28 and earlier

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

DjVuLibre Project · DjVuLibreversion=djvulibre-3.5.28 and earlier

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1204.002Malicious 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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