Bug 1933737 (CVE-2020-27067) - CVE-2020-27067 kernel: use after free due to a race condition may lead to local escalation of privilege
Summary: CVE-2020-27067 kernel: use after free due to a race condition may lead to loc...
Alias: CVE-2020-27067
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1933738 1940645 1940647 1940648
Blocks: 1933739
TreeView+ depends on / blocked
Reported: 2021-03-01 15:24 UTC by Marian Rehak
Modified: 2021-11-09 15:39 UTC (History)
43 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw use-after-free in the Linux kernel l2tp subsystem was found in the way user initialize and use vpn connection over l2tp. A local user could use this flaw to escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Clone Of:
Last Closed: 2021-11-09 15:39:23 UTC

Attachments (Terms of Use)

Description Marian Rehak 2021-03-01 15:24:35 UTC
In the l2tp subsystem, there is a possible use after free due to a race condition, which could lead to local escalation of privilege with System execution privileges needed.



Comment 1 Marian Rehak 2021-03-01 15:25:38 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1933738]

Comment 2 Justin M. Forbes 2021-03-02 14:09:10 UTC
This was fixed for Fedora with the 4.13.6 stable kernel updates.

Comment 5 Alex 2021-03-18 19:07:56 UTC

To mitigate this issue, prevent the module l2tp_core from being loaded. Please see https://access.redhat.com/solutions/41278 for information on how to blacklist a kernel module to prevent it from loading automatically.

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