SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

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…

HIGH 7.8EPSS 0.36%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.36% probability · 30th percentile
CISA KEV
Not listed
Weakness
CWE-416
Affected
netapp/solidfire baseboard management controller · linux/linux kernel · netapp/cloud backup · netapp/h410c firmware · netapp/h300s firmware · netapp/h500s firmware · netapp/h700s firmware · netapp/h300e firmware · netapp/h500e firmware · netapp/h700e firmware · netapp/h410s firmware
Source
security@xen.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.