Description
The Open Phone Abstraction Library (opal), as used by (1) Ekiga before 2.0.10 and (2) OpenH323 before 2.2.4, allows remote attackers to cause a denial of service (crash) via an invalid Content-Length header field in Session Initiation Protocol (SIP) packets, which causes a \0 byte to be written to an "attacker-controlled address."
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | opal +1 | 2.2.2-1.1.0.1 | RHSA-2007:0957 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhel Productivity 5 | opal +1 | 2.2.2-1.1.0.1 | RHSA-2007:0957 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- OpenH323 Opal SIP Protocol - Remote Denial of Service EDB-9240 · dos · Jul 24, 2009 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- RHSA-2007:0957 Red Hat Security Advisory: opal security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
References
- 27118 third-party-advisory
- 27271 third-party-advisory
- 1018776 vdb-entry
- 25955 vdb-entry
- 27129 third-party-advisory
- MDKSA-2007:205 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=296371
- 28380 third-party-advisory
- 41637 vdb-entry
- RHSA-2007:0957 vendor-advisory
- [ekiga-list] 20070917 [ANNOUNCE] Ekiga 2.0.10 released mailing-list
- USN-562-1 vendor-advisory
- oval:org.mitre.oval:def:11398 vdb-entry signature
- http://www.s21sec.com/avisos/s21sec-037-en.txt
- 20071011 S21SEC-037-en: OPAL SIP Protocol Remote Denial of Service mailing-list
- SUSE-SR:2007:021 vendor-advisory
- ADV-2007-3413 vdb-entry
- ADV-2007-3414 vdb-entry
- 9240 exploit
- 27524 third-party-advisory
- http://openh323.cvs.sourceforge.net/openh323/opal/src/sip/sippdu.cxx?r1=2.83.2.19&r2=2.83.2.20
- 27128 third-party-advisory