qemu: CVE-2020-27821: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c

Debian Bug report logs - #977616
qemu: CVE-2020-27821: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c

Reply or subscribe to this bug.

Toggle useless messages

Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Salvatore Bonaccorso <carnil@debian.org>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: qemu: CVE-2020-27821: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c

Date: Thu, 17 Dec 2020 21:10:48 +0100

Source: qemu
Version: 1:5.2+dfsg-2
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil@debian.org, Debian Security Team <team@security.debian.org>
Control: found -1 1:5.1+dfsg-4

Hi,

The following vulnerability was published for qemu.

CVE-2020-27821[0]:
| A flaw was found in the memory management API of QEMU during the
| initialization of a memory region cache. This issue could lead to an
| out-of-bounds write access to the MSI-X table while performing MMIO
| operations. A guest user may abuse this flaw to crash the QEMU process
| on the host, resulting in a denial of service. This flaw affects QEMU
| versions prior to 5.2.0.

There are several issues here. First the above MITRE description
claims this affects version prior to 5.2.0 but 5.2 seems equally
affected still.

commit in [1] tracked this as fixed relating to upstream commit [2].
But it looks that further analysis did track down the issue leading to
[3] and the fixing commit beeing [4]. 


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2020-27821
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-27821
[1] https://tracker.debian.org/news/1200013/accepted-qemu-152dfsg-1-source-into-unstable/
[2] https://git.qemu.org/?p=qemu.git;a=commit;h=1370d61ae3c9934861d2349349447605202f04e9
[3] https://www.openwall.com/lists/oss-security/2020/12/16/6
[4] https://git.qemu.org/?p=qemu.git;a=commit;h=4bfb024bc76973d40a359476dc0291f46e435442


Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore

Send a report that this bug log contains spam.