CVE-2021-25801Public exploit

Application crash via unchecked AVI subindex type

Published Jul 26, 2021 · Updated Aug 3, 2024

Out-of-bounds read in __Parse_indx in VideoLAN VLC media player 3.0.11 allows attackers to crash VLC via a crafted AVI file. The AVI demuxer accepts a super-index target without confirming that the referenced chunk is an index chunk of the expected size, then reads field-index members beyond the smaller object. A user must open the crafted file; the demonstrated consequence is an access violation and player crash, with no integrity impact established.

CVSS severity7.1
High
EPSS probability1.52%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in __Parse_indx in VideoLAN VLC media player 3.0.11 allows attackers to crash VLC via a crafted AVI file. The AVI demuxer accepts a super-index target without confirming that the referenced chunk is an index chunk of the expected size, then reads field-index members beyond the smaller object. A user must open the crafted file; the demonstrated consequence is an access violation and player crash, with no integrity impact established.

The record

CVE
CVE-2021-25801
Published
Jul 26, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 26, 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?

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

7.1NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
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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