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redhatcveRedhat.comRH:CVE-2021-47111
HistoryMar 16, 2024 - 7:07 p.m.

CVE-2021-47111

2024-03-1619:07:33
redhat.com
access.redhat.com
9
linux kernel
vulnerability
resolved
xen-netback
use-after-free
reference
rx
task thread
xsa-374
cve-2021-28691

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

6.3 Medium

AI Score

Confidence

Low

4.6 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:L/Au:N/C:P/I:P/A:P

0.0004 Low

EPSS

Percentile

14.1%

In the Linux kernel, the following vulnerability has been resolved: xen-netback: take a reference to the RX task thread Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it’s needed. This is XSA-374 / CVE-2021-28691.

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

6.3 Medium

AI Score

Confidence

Low

4.6 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:L/Au:N/C:P/I:P/A:P

0.0004 Low

EPSS

Percentile

14.1%