Bug 2511516

Summary: CVE-2026-45084 opensips: denial of service in presence.handle_publish() from unchecked Content-Type state [fedora-all]
Product: [Fedora] Fedora Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: opensipsAssignee: Peter Lemenkov <lemenkov>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: lemenkov
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["e1318365-dade-44dc-9bce-a98b2f0883cf"]}
Fixed In Version: opensips-3.6.7-1.fc43 opensips-3.6.7-1.fc44 opensips-4.0.0-9.fc45 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-08-05 13:16:30 UTC 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: 2511273    

Description Guilherme de Almeida Suckevicz 2026-08-05 13:07:20 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.

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions 3.4.0 through 3.6.5 contain a denial of service vulnerability in the presence module. When the presence module's handle_publish() function processes a SIP PUBLISH request with an Event: presence header and a message body while the configuration option enable_sphere_check=1 is set, it invokes the get_content_type() macro without first calling parse_content_type_hdr(), causing it to dereference uninitialized or NULL Content-Type parsing state and crash. If a Content-Type header is present but unparsed, msg->content_type->parsed is NULL and is dereferenced as a content_t pointer; if the request lacks a Content-Type header entirely, msg->content_type itself is NULL, and both cases lead to a crash. A remote attacker can therefore cause a denial of service against an affected instance with a single PUBLISH request over UDP or TCP, using either a valid Content-Type: application/pidf+xml request or one with the header removed, and the vulnerable code path itself does not enforce authentication (though a deployment's routing configuration may require it before this route is reached). The issue has been fixed in version 3.6.6 and 4.0.0-rc1.
Comment 1 Peter Lemenkov 2026-08-05 13:16:30 UTC 
OpenSIPS in Fedora is not affected — every active branch already carries the fix:

- rawhide/f45: opensips-4.0.0-9.fc45
- f44: opensips-3.6.7-1.fc44 (built 2026-06-24)
- f43: opensips-3.6.7-1.fc43 (built 2026-06-24)

There are no EPEL branches for this package, so the above is the full scope of [fedora-all].

Verified against upstream git rather than the advisory version claims. The fix is two commits on the 3.6 branch, de5071a48 ("presence: make sure Content-Type is parsed") and ec38f4f01 ("presence: handle case when Content-Type is missing"), both dated 2026-05-13; git tag --contains puts both first in 3.6.6 and also in 3.6.7. The equivalent pair on master (73279c3fe, 91e13270e) first appears in 4.0.0-rc1 and is present in 4.0.0. So the advisory's "fixed in 3.6.6 and 4.0.0-rc1" is accurate.

Also worth noting that the vulnerable path is not reachable in a default configuration: the presence module's enable_sphere_check parameter is backed by sphere_enable, which is initialised to 0, so handle_publish() only reaches the affected get_content_type() call when a deployment explicitly sets modparam("presence", "enable_sphere_check", 1).

Closing CURRENTRELEASE.