CVE-2020-18831Public exploit

Metadata-processing crash via underflowed PNG buffer offset

Published Aug 22, 2023 · Updated Oct 4, 2024

Out-of-bounds read in Exiv2 0.27.1 allows remote attackers to crash metadata processing via a crafted PNG file. In pngimage.cpp, tEXtToDataBuf receives an underflowed dataOffset-minus-name-length value of 0xFFFFFFFF and reads beyond the buffer. Exploitation requires Exiv2 to process the file; the demonstrated consequence is a segmentation-fault crash, while other impacts remain unspecified.

CVSS severity7.8
High
EPSS probability0.80%
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 Exiv2 0.27.1 allows remote attackers to crash metadata processing via a crafted PNG file. In pngimage.cpp, tEXtToDataBuf receives an underflowed dataOffset-minus-name-length value of 0xFFFFFFFF and reads beyond the buffer. Exploitation requires Exiv2 to process the file; the demonstrated consequence is a segmentation-fault crash, while other impacts remain unspecified.

The record

CVE
CVE-2020-18831
Published
Aug 22, 2023
Updated
Oct 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 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

5.3SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application 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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