CVE-2020-20445Public exploitNetwork attack vector

Media-processing crash via unchecked LPC denominators

Published May 25, 2021 · Updated Aug 4, 2024

Divide by zero in FFmpeg 4.2 allows remote authenticated users to crash media-processing services through crafted LPC input. The compute_ref_coefs routine divides -gen1[0] by an LPC prediction error without checking whether the denominator is zero, while ff_lpc_calc_ref_coefs_f divides signal by an unchecked average error. The target must process attacker-controlled media through the LPC coefficient path; exploitation terminates the affected process without reported data disclosure or modification.

CVSS severity6.5
Medium
EPSS probability1.65%
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 FFmpeg 4.2 allows remote authenticated users to crash media-processing services through crafted LPC input. The compute_ref_coefs routine divides -gen1[0] by an LPC prediction error without checking whether the denominator is zero, while ff_lpc_calc_ref_coefs_f divides signal by an unchecked average error. The target must process attacker-controlled media through the LPC coefficient path; exploitation terminates the affected process without reported data disclosure or modification.

The record

CVE
CVE-2020-20445
Published
May 25, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-369, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 25, 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

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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 privilegesauthenticated

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:L/UI:N/S:U/C:N/I:N/A:H
4.0NIST NVDAV:N/AC:L/Au:S/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.

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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
Privilegesauthenticated
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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