Description
The pit_ioport_read function in the Programmable Interval Timer (PIT) emulation in i8254.c in KVM 83 does not properly use the pit_state data structure, which allows guest OS users to cause a denial of service (host OS crash or hang) by attempting to read the /dev/port file.
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 5.0 | kvm | 72+dfsg-5~lenny5 | DSA-2010-1 |
| Debian 5.0 | linux-2.6 | 2.6.26-21lenny3 | DSA-1996-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | rhev-hypervisor +1 | 5.4-2.1.8.el5_4rhev2_1 | RHSA-2010:0095 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhel Virtualization 5 | kvm +3 | 83-105.el5_4.22 | RHSA-2010:0088 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.35.1-4 | — |
| Azure Linux 2 (CBL-Mariner) | kernel | 5.10.78.1-1 | — |
Advisories 4
- RHSA-2010:0095 Red Hat Security Advisory: rhev-hypervisor security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2010:0088 Red Hat Security Advisory: kvm security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- DSA-1996-1 linux-2.6 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2010-1 kvm - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- 38158 vdb-entry
- USN-914-1 vendor-advisory
- ADV-2010-0638 vdb-entry
- RHSA-2010:0088 vendor-advisory
- 38922 third-party-advisory
- [oss-security] 20100202 Re: CVE request - kvm: cat /dev/port in the guest can cause host DoS mailing-list
- DSA-1996 vendor-advisory
- oval:org.mitre.oval:def:11095 vdb-entry signature
- https://bugzilla.redhat.com/show_bug.cgi?id=560887
- [oss-security] 20100202 CVE request - kvm: cat /dev/port in the guest can cause host DoS mailing-list
- [kvm] 20100129 KVM: PIT: control word is write-only mailing-list
- RHSA-2010:0095 vendor-advisory
- 38492 third-party-advisory