CyberSecBulletin
CVE-2025-57767NVD status: Analyzed

asterisk: Incorrect Check of Function Return Value

Published Updated By the CyberSecBulletin desk

CVE-2025-57767 is a high-severity incorrect check of function return value vulnerability in asterisk, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected asterisk versions: < 22.5.2; < 21.10.2; < 20.15.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of asterisk you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Asteriskasterisk< 22.5.2; < 21.10.2; < 20.15.2Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).

Official description

Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 20.15.2, 21.10.2, and 22.5.2, if a SIP request is received with an Authorization header that contains a realm that wasn't in a previous 401 response's WWW-Authenticate header, or an Authorization header with an incorrect realm was received without a previous 401 response being sent, the get_authorization_header() function in res_pjsip_authenticator_digest will return a NULL. This wasn't being checked before attempting to get the digest algorithm from the header which causes a SEGV. This issue has been patched in versions 20.15.2, 21.10.2, and 22.5.2. There are no workarounds.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Check of Function Return Value

The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.

How developers prevent this class of flaw

  • Use a language or compiler that uses exceptions and requires the catching of those exceptions.
  • Properly check all functions which return a value.
  • When designing any function make sure you return a value or throw an exception in case of an error.

More Incorrect Check of Function Return Value vulnerabilities (CWE-253)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in asterisk

All asterisk vulnerabilities

Recent Incorrect Check of Function Return Value vulnerabilities

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