CVE-2020-23904Public exploit

Encoder crash via unchecked WAV read length

Published Nov 10, 2021 · Updated Aug 4, 2024

Stack buffer overflow in Xiph Speex 1.2 allows context-dependent attackers to crash speexenc via a crafted WAV file. The reported locus is speexenc.c line 122, where fread copies to_read bytes from the WAV input into the stack-resident input buffer without a shown bounds check. A victim must run the demo encoder on the file; the maintainer could not reproduce the report, so only a process crash is established.

CVSS severity5.5
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in Xiph Speex 1.2 allows context-dependent attackers to crash speexenc via a crafted WAV file. The reported locus is speexenc.c line 122, where fread copies to_read bytes from the WAV input into the stack-resident input buffer without a shown bounds check. A victim must run the demo encoder on the file; the maintainer could not reproduce the report, so only a process crash is established.

The record

CVE
CVE-2020-23904
Published
Nov 10, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
3.3SUSECVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/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-787Out-of-bounds Write
T1204.002User Execution: Malicious 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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