Use After Free in Linux
CVE-2021-28691
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.
Vulnerability class: Use-After-Free
EPSS: 0.004 (28.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Linux — versions unspecified, 5.5.0, next of 5.12.2
- Linux Linux_kernel
- Netapp Cloud_backup
- Netapp H300e
- Netapp H300e_firmware
- Netapp H300s
- Netapp H300s_firmware
- Netapp H410c
- Netapp H410c_firmware
- Netapp H410s
Weakness classification (CWE)
References
- security@xen.org (Third Party Advisory, x_refsource_MISC)
- security@xen.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
- security@xen.org (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-28691?
- CVE-2021-28691 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2021-06-29.
- How severe is CVE-2021-28691?
- High severity. CVSS v3 base score is 7.8 out of 10.