CVE-2021-43301Network attack vector

Memory corruption via unchecked playlist filename length

Published Feb 16, 2022 · Updated Nov 4, 2025

Stack-based buffer overflow in Teluu PJSIP 2.11.1 and earlier allows attackers to corrupt stack memory via oversized playlist filenames. The pjsua_playlist_create path passes each file_names element to pjmedia_wav_playlist_create, which copied its declared length into a PJ_MAXPATH stack buffer before checking the bound. A consuming application must pass an attacker-controlled filename to the API; successful triggering crashes the process or corrupts memory in that application.

CVSS severity9.8
Critical
EPSS probability2.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Teluu PJSIP 2.11.1 and earlier allows attackers to corrupt stack memory via oversized playlist filenames. The pjsua_playlist_create path passes each file_names element to pjmedia_wav_playlist_create, which copied its declared length into a PJ_MAXPATH stack buffer before checking the bound. A consuming application must pass an attacker-controlled filename to the API; successful triggering crashes the process or corrupts memory in that application.

The record

CVE
CVE-2021-43301
Published
Feb 16, 2022
Updated
Nov 4, 2025
Vendor
Teluu
Product
PJSIP
Classifications
CWE-787, CWE-121
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 16, 2022CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=2.11.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Teluu · PJSIPversion=unspecified <=2.11.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/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-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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