CVE-2021-46312Public exploitNetwork attack vector

Process crash via zero gray-level divisor

Published Aug 22, 2023 · Updated Nov 4, 2025

Divide by zero in DjVuLibre 3.5.28 allows attackers to crash c44 by supplying a crafted bitmap with a single gray level. IWBitmap::Encode::init sets g to get_grays() minus one, then uses g as the divisor in its gray-conversion loop without rejecting zero. A user must process the crafted input; the resulting SIGFPE terminates the c44 process, with no reported confidentiality or integrity impact.

CVSS severity6.5
Medium
EPSS probability1.04%
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 DjVuLibre 3.5.28 allows attackers to crash c44 by supplying a crafted bitmap with a single gray level. IWBitmap::Encode::init sets g to get_grays() minus one, then uses g as the divisor in its gray-conversion loop without rejecting zero. A user must process the crafted input; the resulting SIGFPE terminates the c44 process, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2021-46312
Published
Aug 22, 2023
Updated
Nov 4, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-369, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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
T1499Endpoint Denial of Service

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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