CVE-2025-57767: Asterisk is an open source private branch exchange and telephony toolkit

This month

HIGH 7.5REMOTEUPGRADE

CVE-2025-57767 is a high-severity flaw (CVSS 7.5) affecting asterisk. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-253
Published	2025-08-28
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: sangoma

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-08-28 16:15 UTCPublished CVE record published
2026-06-17 09:43 UTCUpdated Record last modified

sangoma asterisk UPGRADE

Affected: < 20.15.2 · >= 21.0.0 and < 21.10.2 · >= 22.0.0 and < 22.5.2

Fixed in: 20.15.2, 21.10.2, 22.5.2

Safe to downgrade to: a release before 21.0.0

1. Check installed version

apt-cache policy asterisk || rpm -q asterisk || asterisk --version

2. UPGRADE to 20.15.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade asterisk

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade asterisk

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 21.0.0 (Debian / Ubuntu)

apt-cache madison asterisk sudo apt install asterisk=<VERSION_BEFORE_21.0.0> sudo apt-mark hold asterisk

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list asterisk sudo dnf downgrade asterisk-<VERSION_BEFORE_21.0.0> sudo dnf versionlock add asterisk

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-57767?

asterisk: upgrade to 20.15.2, 21.10.2, 22.5.2. Exact commands for each OS are on this page.

Is CVE-2025-57767 being exploited?

CVE-2025-57767 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-57767 affect?

CVE-2025-57767 affects asterisk. Severity is high (CVSS 7.5). 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

How urgent is CVE-2025-57767?

Priority 40/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-1131 HIGH 7.8 UPGRADE DOWNGRADE A local privilege escalation vulnerability exists in the safe_asterisk script included with the Asterisk toolk
CVE-2026-23741 NONE 0.0 UPGRADE UPGRADE Asterisk is an open source private branch exchange and telephony toolkit
CVE-2026-23740 NONE 0.0 DOWNGRADE UPGRADE Asterisk is an open source private branch exchange and telephony toolkit
CVE-2026-23739 LOW 2.0 UPGRADE UPGRADE Asterisk is an open source private branch exchange and telephony toolkit
CVE-2026-23738 LOW 3.5 UPGRADE UPGRADE Asterisk is an open source private branch exchange and telephony toolkit

References

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