Bug 2539363

Summary:	CVE-2026-84975 asterisk: PJSIP: Server impersonation via TLS certificate hostname bypass [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Vladimir Vasilev <vvasilev>
Component:	asterisk	Assignee:	Peter Lemenkov <lemenkov>
Status:	ON_QA ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	rawhide	CC:	bennie.joubert, jsmith.fedora, lemenkov
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["2d525c41-f86e-4324-bb7a-18b9e3652867"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2538911

Description Vladimir Vasilev 2026-09-23 11:36:57 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

PJSIP is a free and open source multimedia communication library written in C. In 2.17 and earlier, the OpenSSL and GnuTLS backends in pjlib/src/pj/ssl_sock_ossl.c and pjlib/src/pj/ssl_sock_gtls.c copy DNS SubjectAltName values with string functions that recalculate their length and truncate an embedded NUL byte. With server verification enabled through --tls-verify-server for the PJSIP TLS/SIPS transport, a certificate containing a DNS SubjectAltName formed from the target hostname prefix followed by an embedded NUL and an attacker-controlled suffix can therefore be accepted for the prefix hostname. An attacker who possesses such a certificate from a trusted issuer and can intercept the connection can impersonate the target server, complete the SIP session, and receive REGISTER credentials. The mbedTLS backend is not affected because it preserves the explicit string length. No fixed version is available as of this review.

Comment 1 Fedora Update System 2026-09-23 15:45:28 UTC

FEDORA-2026-0a7abaa716 (asterisk-23.5.0-5.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-0a7abaa716

Comment 2 Fedora Update System 2026-09-24 01:35:17 UTC

FEDORA-2026-0a7abaa716 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-0a7abaa716`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-0a7abaa716

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 3 Fedora Update System 2026-09-26 01:47:29 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-09-29 01:34:06 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-09-30 01:52:41 UTC

FEDORA-2026-91259c13b9 has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-91259c13b9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-91259c13b9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.