Bug 1961300 (CVE-2021-33033) - CVE-2021-33033 kernel: use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c
Summary: CVE-2021-33033 kernel: use-after-free in cipso_v4_genopt in net/ipv4/cipso_ip...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2021-33033
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1966980 1961301 1967720 1967721 1967722 1967723 1967724 1967725
Blocks: 1961302
TreeView+ depends on / blocked
 
Reported: 2021-05-17 16:31 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-07-26 16:58 UTC (History)
47 users (show)

Fixed In Version: Kernel 5.12
Doc Type: If docs needed, set a value
Doc Text:
A flaw use-after-free in the Linux kernel CIPSO network packet labeling protocol functionality was found in the way user open local network connection with the usage of the security labeling that is IP option number 134. A local user could use this flaw to crash the system or possibly escalate their privileges on the system.
Clone Of:
Environment:
Last Closed: 2021-07-21 03:54:44 UTC


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2021:2897 0 None None None 2021-07-26 16:58:58 UTC
Red Hat Product Errata RHSA-2021:2725 0 None None None 2021-07-21 01:07:49 UTC
Red Hat Product Errata RHSA-2021:2726 0 None None None 2021-07-21 01:08:23 UTC

Description Guilherme de Almeida Suckevicz 2021-05-17 16:31:57 UTC
The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled. This leads to writing an arbitrary value.

References:
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e

Upstream patches:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad5d07f4a9cd671233ae20983848874731102c08
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8

Comment 1 Guilherme de Almeida Suckevicz 2021-05-17 16:32:34 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1961301]

Comment 2 Justin M. Forbes 2021-05-17 20:31:42 UTC
This was fixed for Fedora users with the 5.11.14 stable kernel updates.

Comment 28 errata-xmlrpc 2021-07-21 01:07:49 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:2725 https://access.redhat.com/errata/RHSA-2021:2725

Comment 29 errata-xmlrpc 2021-07-21 01:08:23 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:2726 https://access.redhat.com/errata/RHSA-2021:2726

Comment 30 Product Security DevOps Team 2021-07-21 03:54:44 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-33033


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