Description
The protocol_client_msg function in vnc.c in the VNC server in (1) Qemu 0.9.1 and earlier and (2) KVM kvm-79 and earlier allows remote attackers to cause a denial of service (infinite loop) via a certain message.
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | qemu | 0.9.1-9 | — |
| Debian 13 | qemu | 0.9.1-9 | — |
| Debian 12 | qemu | 0.9.1-9 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | qemu +1 | 2.6.1-1.5 | openSUSE-SU-2024:10285-1, openSUSE-SU-2024:10233-1 |
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
- QEMU 0.9 / KVM 36/79 - VNC Server Remote Denial of Service EDB-32675 · dos · Dec 22, 2008 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- openSUSE-SU-2024:10285-1 qemu-linux-user-2.6.1-1.5 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10233-1 qemu-2.6.1-1.5 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 35062 third-party-advisory
- 1021489 vdb-entry
- 4803 third-party-advisory
- ADV-2008-3488 vdb-entry
- FEDORA-2008-11705 vendor-advisory
- 33303 third-party-advisory
- 34642 third-party-advisory
- 33293 third-party-advisory
- USN-776-1 vendor-advisory
- 33350 third-party-advisory
- http://www.coresecurity.com/content/vnc-remote-dos
- SUSE-SR:2009:002 vendor-advisory
- 33568 third-party-advisory
- SUSE-SR:2009:008 vendor-advisory
- 20081222 CORE-2008-1210: Qemu and KVM VNC server remote DoS mailing-list
- 1021488 vdb-entry
- 32910 vdb-entry
- ADV-2008-3489 vdb-entry
- qemu-kvm-protocolclientmsg-dos(47561) vdb-entry