CVE-2021-38291Network attack vector

Application crash via negative audio frame duration

Published Aug 12, 2021 · Updated Aug 4, 2024

Reachable assertion in FFmpeg commit de8e6e67e7523e48bb27ac224a0b446df05e1640 allows remote attackers to crash applications. For ADPCM_MS audio with an extremely high channel count, get_audio_frame_duration() returns a negative duration that av_get_audio_frame_duration() propagates into an assertion in libavutil/mathematics.c. A crafted audio sample must be processed by an application built with the affected code; the assertion terminates that process, with no reported confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability2.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Reachable assertion in FFmpeg commit de8e6e67e7523e48bb27ac224a0b446df05e1640 allows remote attackers to crash applications. For ADPCM_MS audio with an extremely high channel count, get_audio_frame_duration() returns a negative duration that av_get_audio_frame_duration() propagates into an assertion in libavutil/mathematics.c. A crafted audio sample must be processed by an application built with the affected code; the assertion terminates that process, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2021-38291
Published
Aug 12, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-617, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 12, 2021CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo