CVE-2021-3735
First published: Tue Aug 24 2021(Updated: )
A deadlock issue was found in the AHCI controller device (ich9-ahci) of QEMU while handling a host-to-device Register FIS (Frame Information Structure) packet from the guest. The bug is triggered on a software reset (ahci_reset_port) in the handle_reg_h2d_fis() function [1]. A privileged user inside the guest could use this flaw to hang the QEMU process on the host, resulting in a denial of service condition. [1] <a href="https://github.com/qemu/qemu/blob/v6.1.0-rc4/hw/ide/ahci.c#L1215">https://github.com/qemu/qemu/blob/v6.1.0-rc4/hw/ide/ahci.c#L1215</a>
Credit: secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| debian/qemu | <=1:3.1+dfsg-8+deb10u8<=1:3.1+dfsg-8+deb10u11<=1:5.2+dfsg-11+deb11u3<=1:5.2+dfsg-11+deb11u2<=1:7.2+dfsg-7+deb12u2<=1:8.1.1+ds-2<=1:8.1.2+ds-1 | |
| QEMU qemu | =6.1.0-rc4 | |
| Debian Debian Linux | =10.0 | |
| Debian Debian Linux | =11.0 |
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Reference Links
- https://github.com/qemu/qemu/blob/v6.1.0-rc4/hw/ide/ahci.c#L1215
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1997217
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1997215
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1997184#c4
- https://bugzilla.redhat.com/show_bug.cgi?id=1997184
- https://security-tracker.debian.org/tracker/CVE-2021-3735
- https://access.redhat.com/security/cve/CVE-2021-3735
Frequently Asked Questions
What is CVE-2021-3735?
CVE-2021-3735 is a deadlock issue found in the AHCI controller device of QEMU.
How does CVE-2021-3735 occur?
CVE-2021-3735 occurs on a software reset (ahci_reset_port) while handling a host-to-device Register FIS packet from the guest.
Who is affected by CVE-2021-3735?
Users of QEMU versions 1:3.1+dfsg-8+deb10u8 to 1:3.1+dfsg-8+deb10u11, 1:5.2+dfsg-11+deb11u3 to 1:5.2+dfsg-11+deb11u2, 1:7.2+dfsg-7+deb12u2, 1:8.1.1+ds-2, and 1:8.1.2+ds-1, as well as QEMU version 6.1.0-rc4 and Debian Linux versions 10.0 and 11.0 are affected by CVE-2021-3735.
What is the severity of CVE-2021-3735?
CVE-2021-3735 has a severity score of 4.4 out of 10, which is considered medium.
How can I fix CVE-2021-3735?
There is currently no known fix for CVE-2021-3735. It is recommended to update to a patched version of QEMU when it becomes available.
- collector/redhat-bugzilla
- alias/CVE-2021-3735
- collector/security-tracker-debian
- collector/nvd-index
- agent/severity
- agent/references
- agent/weakness
- agent/author
- agent/tags
- agent/description
- agent/type
- agent/event
- agent/first-publish-date
- agent/softwarecombine
- agent/last-modified-date
- package-manager/debian
- vendor/qemu
- canonical/qemu qemu
- version/qemu qemu/6.1.0-rc4
- vendor/debian
- canonical/debian debian linux
- version/debian debian linux/10.0
- version/debian debian linux/11.0