CVE-2020-27821: Buffer Overflow
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.
Other sources
A heap buffer overflow was found in the Message Signaled Interrupt (MSI-X) device support of QEMU. The overflow could occur due to an out-of-bounds write of the MSIX table while performing MSI-X mmio operations in msixtablemmiowrite(). A guest user may exploit this flaw to crash the QEMU process on the host, resulting in a denial of service condition.
Upstream fix: https://git.qemu.org/?p=qemu.git;a=commit;h=4bfb024bc76973d40a359476dc0291f46e435442
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/qemuto a version that resolves this vulnerability.Fixed in 5.2.0 - Upgrade
Upgrade
debian/qemuto a version that resolves this vulnerability.Fixed in 1:5.2+dfsg-11+deb11u3Fixed in 1:5.2+dfsg-11+deb11u2Fixed in 1:7.2+dfsg-7+deb12u12Fixed in 1:9.2.2+ds-1Fixed in 1:10.0.0~rc2+ds-2 - Upgrade
Upgrade
alpine/qemuto a version that resolves this vulnerability.Fixed in 5.2.0-r0 - Upgrade
Upgrade
QEMUto a version that resolves this vulnerability.Fixed in 5.2.0Patch 4bfb024bc76973d40a359476dc0291f46e435442
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2020-27821?
CVE-2020-27821 is a vulnerability in the memory management API of QEMU that could lead to an out-of-bounds write access and crashing of the QEMU process.
How severe is CVE-2020-27821?
CVE-2020-27821 has a severity score of 5.7, which is considered medium severity.
Which software is affected by CVE-2020-27821?
QEMU version up to exclusive 5.2.0 is affected by CVE-2020-27821.
How can I fix CVE-2020-27821?
To mitigate CVE-2020-27821, upgrade QEMU to version 5.2.0 or higher.
Where can I find more information about CVE-2020-27821?
You can find more information about CVE-2020-27821 at the following references: [Link 1](https://www.cve.org/CVERecord?id=CVE-2020-27821), [Link 2](https://nvd.nist.gov/vuln/detail/CVE-2020-27821), [Link 3](https://www.openwall.com/lists/oss-security/2020/12/16/6), [Link 4](https://bugzilla.redhat.com/show_bug.cgi?id=1902651), [Link 5](https://access.redhat.com/errata/RHBA-2021:0639)