Description
Off-by-one error in monitor.c in Qemu 0.9.1 might make it easier for remote attackers to guess the VNC password, which is limited to seven characters where eight was intended.
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 | 0.9.1-10 | — |
| Debian 13 | qemu | 0.9.1-10 | — |
| Debian 12 | qemu | 0.9.1-10 | — |
| Debian 6.0 | kvm | 72+dfsg-5+squeeze1 | DTSA-203-1 |
| Debian 5.0 | kvm | 72+dfsg-5~lenny3 | DSA-1907-1 |
Advisories 2
- DSA-1907-1 kvm - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DTSA-203-1 kvm - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- [qemu-devel] 20081210 Re: [RESEND] [PATCH v2] Fix off-by-one bug limiting VNC passwords to 7 chars mailing-list
- 35062 third-party-advisory
- qemu-monitor-weak-security(47683) vdb-entry
- [qemu-devel] 20081123 [PATCH] Fix off-by-one bug limiting VNC passwords to 7 chars mailing-list
- 34642 third-party-advisory
- http://svn.savannah.gnu.org/viewvc/?view=rev&root=qemu&revision=5966
- 33020 vdb-entry
- USN-776-1 vendor-advisory
- SUSE-SR:2009:002 vendor-advisory
- 33568 third-party-advisory
- SUSE-SR:2009:008 vendor-advisory
- http://svn.savannah.gnu.org/viewvc/trunk/monitor.c?root=qemu&r1=5966&r2=5965&pathrev=5966