CVE-2021-20257
First published: Thu Feb 18 2021(Updated: )
An infinite loop flaw was found in the e1000 NIC emulator of the QEMU. This issue occurs while processing transmits (tx) descriptors in process_tx_desc if various descriptor fields are initialized with invalid values. This flaw allows a guest to consume CPU cycles on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Credit: secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| QEMU qemu | <6.2.0 | |
| Fedoraproject Fedora | =33 | |
| Redhat Openstack Platform | =10.0 | |
| Redhat Openstack Platform | =13.0 | |
| Redhat Enterprise Linux | =6.0 | |
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux For Ibm Z Systems | =8.0 | |
| Redhat Enterprise Linux For Power Little Endian | =8.0 | |
| Redhat Codeready Linux Builder | ||
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux For Ibm Z Systems | =8.0 | |
| Redhat Enterprise Linux For Power Little Endian | =8.0 | |
| Debian Debian Linux | =10.0 | |
| All of | ||
| Redhat Codeready Linux Builder | ||
| Any of | ||
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux For Ibm Z Systems | =8.0 | |
| Redhat Enterprise Linux For Power Little Endian | =8.0 | |
| debian/qemu | 1:5.2+dfsg-11+deb11u3 1:5.2+dfsg-11+deb11u2 1:7.2+dfsg-7+deb12u7 1:9.1.1+ds-2 1:9.1.1+ds-4 |
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Reference Links
- https://bugzilla.redhat.com/show_bug.cgi?id=1930087
- https://github.com/qemu/qemu/commit/3de46e6fc489c52c9431a8a832ad8170a7569bd8
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
- https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg07428.html
- https://security.gentoo.org/glsa/202208-27
- https://security.netapp.com/advisory/ntap-20220425-0003/
- https://www.openwall.com/lists/oss-security/2021/02/25/2
- https://launchpad.net/bugs/cve/CVE-2021-20257
- https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg03595.html
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1930089
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1930094
- https://access.redhat.com/support/policy/updates/errata/
- https://access.redhat.com/errata/RHSA-2021:5238
- https://access.redhat.com/security/cve/cve-2021-20257
- https://access.redhat.com/errata/RHSA-2022:0081
- https://git.qemu.org/?p=qemu.git;a=commit;h=3de46e6fc489c52c9431a8a832ad8170a7569bd8
- https://security-tracker.debian.org/tracker/CVE-2021-20257
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20257
- https://nvd.nist.gov/vuln/detail/CVE-2021-20257
- https://ubuntu.com/security/CVE-2021-20257
Frequently Asked Questions
What is CVE-2021-20257?
CVE-2021-20257 is an infinite loop flaw in the e1000 NIC emulator of QEMU, which allows a guest to consume CPU cycles on the host, resulting in a denial of service.
Which software is affected by CVE-2021-20257?
QEMU, Fedora, Redhat Openstack Platform, Redhat Enterprise Linux, Redhat Codeready Linux Builder, and Debian Linux are affected by CVE-2021-20257.
What is the severity of CVE-2021-20257?
CVE-2021-20257 has a severity rating of medium (6.5).
How can I fix CVE-2021-20257 in Ubuntu?
To fix CVE-2021-20257 in Ubuntu, update the 'qemu' package to version 2.11+dfsg-1ubuntu7.37 (for Bionic), 4.2-3ubuntu6.17 (for Focal), or 5.0-5ubuntu9.9 (for Groovy).
How can I fix CVE-2021-20257 in Debian?
To fix CVE-2021-20257 in Debian, update the 'qemu' package to version 3.1+dfsg-8+deb10u11, 5.2+dfsg-11+deb11u3, 5.2+dfsg-11+deb11u2, 7.2+dfsg-7+deb12u2, or 8.1.2+ds-1.
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