CVE-2021-28691: Use After Free
First published: Tue Jun 29 2021(Updated: )
Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.
Credit: security@xen.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Kernel | >=5.5.0<5.12.2 | |
| netapp cloud backup | ||
| netapp h410c firmware | ||
| netapp h410c | ||
| netapp h300s firmware | ||
| netapp h300s | ||
| NetApp H500S Firmware | ||
| netapp h500s | ||
| netapp h700s firmware | ||
| netapp h700s | ||
| netapp h300e firmware | ||
| netapp h300e | ||
| netapp h500e firmware | ||
| netapp h500e | ||
| netapp h700e firmware | ||
| netapp h700e | ||
| netapp h410s firmware | ||
| netapp h410s | ||
| All of | ||
| netapp h410c firmware | ||
| netapp h410c | ||
| All of | ||
| netapp h300s firmware | ||
| netapp h300s | ||
| All of | ||
| NetApp H500S Firmware | ||
| netapp h500s | ||
| All of | ||
| netapp h700s firmware | ||
| netapp h700s | ||
| All of | ||
| netapp h300e firmware | ||
| netapp h300e | ||
| All of | ||
| netapp h500e firmware | ||
| netapp h500e | ||
| All of | ||
| netapp h700e firmware | ||
| netapp h700e | ||
| All of | ||
| netapp h410s firmware | ||
| netapp h410s | ||
| debian/linux | 5.10.223-1 5.10.226-1 6.1.123-1 6.1.128-1 6.12.12-1 6.12.15-1 |
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Reference Links
- https://xenbits.xenproject.org/xsa/advisory-374.txt
- https://security.gentoo.org/glsa/202107-30
- https://security.netapp.com/advisory/ntap-20210805-0002/
- https://launchpad.net/bugs/cve/CVE-2021-28691
- https://xenbits.xen.org/xsa/advisory-374.html
- https://security-tracker.debian.org/tracker/CVE-2021-28691
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28691
- https://nvd.nist.gov/vuln/detail/CVE-2021-28691
- https://ubuntu.com/security/CVE-2021-28691
Frequently Asked Questions
What is the severity of CVE-2021-28691?
CVE-2021-28691 has a medium severity level due to the potential for a denial of service attack.
How do I fix CVE-2021-28691?
To fix CVE-2021-28691, upgrade the Linux kernel to version 5.10.223-1, 5.10.226-1, or a later version.
What software is affected by CVE-2021-28691?
CVE-2021-28691 affects the Linux kernel versions between 5.5.0 and 5.12.2 and also impacts specific NetApp firmware versions.
What symptoms indicate an exploitation of CVE-2021-28691?
An exploitation of CVE-2021-28691 can cause the network interface to be disabled and associated kernel threads to terminate unexpectedly.
Is there a workaround for CVE-2021-28691 while I wait to update my system?
A temporary workaround for CVE-2021-28691 is not documented, so updating to the patched versions is recommended as the primary mitigation.
- agent/type
- agent/remedy
- collector/launchpad-cve
- source/Launchpad
- agent/author
- agent/severity
- agent/weakness
- collector/mitre-cve
- source/MITRE
- collector/usn-cve
- source/Ubuntu
- agent/references
- agent/first-publish-date
- agent/description
- agent/event
- agent/last-modified-date
- agent/trending
- agent/source
- collector/nvd-index
- agent/software-canonical-lookup-request
- collector/nvd-cve
- source/NVD
- agent/software-canonical-lookup
- agent/tags
- agent/softwarecombine
- collector/security-tracker-debian
- source/Debian
- vendor/linux
- canonical/linux kernel
- version/linux kernel/5.5.0
- vendor/netapp
- canonical/netapp cloud backup
- canonical/netapp h410c firmware
- canonical/netapp h410c
- canonical/netapp h300s firmware
- canonical/netapp h300s
- canonical/netapp h500s firmware
- canonical/netapp h500s
- canonical/netapp h700s firmware
- canonical/netapp h700s
- canonical/netapp h300e firmware
- canonical/netapp h300e
- canonical/netapp h500e firmware
- canonical/netapp h500e
- canonical/netapp h700e firmware
- canonical/netapp h700e
- canonical/netapp h410s firmware
- canonical/netapp h410s
- package-manager/debian