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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (27.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Linux — versions unspecified, 5.5.0, next of 5.12.2
- 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
- xenbits.xenproject.org/xsa/advisory-374.txt (Third Party Advisory)
- security.gentoo.org/glsa/202107-30 (vendor-advisory, Third Party Advisory)
- security.netapp.com/advisory/ntap-20210805-0002/ (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.