CVE-2020-23558

Application crash via invalid FORMATS plug-in write

Published Sep 16, 2022 · Updated Aug 4, 2024

Out-of-bounds write in IrfanView 4.54's FORMATS plug-in allows local users to crash the application by opening a crafted DCR file. The 32-bit plug-in's ShowPlugInSaveOptions_W routine performs a two-byte write through an invalid address computed from EDI and EAX while reading the file. Exploitation requires a local user to open the crafted image, causing a user-mode access violation and terminating that IrfanView process.

CVSS severity7.8
High
EPSS probability0.33%
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 write in IrfanView 4.54's FORMATS plug-in allows local users to crash the application by opening a crafted DCR file. The 32-bit plug-in's ShowPlugInSaveOptions_W routine performs a two-byte write through an invalid address computed from EDI and EAX while reading the file. Exploitation requires a local user to open the crafted image, causing a user-mode access violation and terminating that IrfanView process.

The record

CVE
CVE-2020-23558
Published
Sep 16, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2022CVE 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

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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