Bug 1992815 (CVE-2021-38209) - CVE-2021-38209 kernel: net/netfilter/nf_conntrack_standalone.c allows observation of changes in any net namespace because these changes are leaked into all other net namespaces
Summary: CVE-2021-38209 kernel: net/netfilter/nf_conntrack_standalone.c allows observa...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2021-38209
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1992817 1994243
Blocks: 1992818
TreeView+ depends on / blocked
 
Reported: 2021-08-11 18:53 UTC by Guilherme de Almeida Suckevicz
Modified: 2022-04-17 21:33 UTC (History)
43 users (show)

Fixed In Version: kernel 5.13-rc1
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the Linux kernel. Observation of changes in any net namespace is possible due to these changes being leaked into all other net namespaces. The highest threat from this vulnerability is to data confidentiality.
Clone Of:
Environment:
Last Closed: 2021-11-08 02:29:26 UTC
Embargoed:

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Description Guilherme de Almeida Suckevicz 2021-08-11 18:53:53 UTC 
The network connection tracking implementation in netfilter module of the Linux kernel allows observation of changes of sysctl settingsin any net namespace as these changes are leaked into all other net namespaces. This is related to the NF_SYSCTL_CT_MAX, NF_SYSCTL_CT_EXPECT_MAX, and NF_SYSCTL_CT_BUCKETS sysctls.

Reference and upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2671fa4dc0109d3fb581bc3078fdf17b5d9080f6
Comment 1 Guilherme de Almeida Suckevicz 2021-08-11 18:54:30 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1992817]
Comment 2 Justin M. Forbes 2021-08-12 13:36:08 UTC 
This was fixed for Fedora with the 5.11.19 stable kernel updates.
Comment 8 juneau 2021-08-17 12:01:02 UTC 
Marking Hosted OCP and Other Services 'notaffected' per kernel analysis.
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