Title: EGI SVG 'ADVISORY' [TLP:WHITE] HIGH risk Linux Kernel release fixing
various software vulnerabilities [EGI-SVG-CVE-2020-25211]
Date: 2021-01-06
Updated: 2021-03-22, 2021-04-06
Affected software and risk
==========================
Various vulnerabilities concerning the Linux kernel including 2 which are
'HIGH' risk
Package : Linux Kernel
CVE ID : CVE-2020-25211, CVE-2020-29661
Bug ID : Red Hat Bugzilla 1877571
CVE-2020-25211 A buffer overflow vulnerability has been announced by RedHat
which may allow a local user to crash the system, compromise data
confidentiality and the integrity of the system. [R 1] [R 2] [R 3] [R 4]
Additionally, this Advisory acts as an 'UPDATE' to the advisory sent on 6th
January 2021 concerning this vulnerability and asking sites to mitigate.
CVE-2020-29661 A locking vulnerability was found in the tty subsystem of the
Linux kernel in drivers/tty/tty_jobctrl.c. This flaw allows a local attacker
to possibly corrupt memory or escalate privileges.
The highest threat from this vulnerability is to confidentiality, integrity, as
well as system availability. [R 7]
Other vulnerabilities may also have been fixed in this release.
Actions required/recommended
============================
Updated packages are available for RHEL 7 and 8 and CentOS 7 & 8
Sites which have not updated already should update as soon as possible.
Component installation information
==================================
Sites should see [R 4] [R 7]
Mitigation for CVE-2020-25211
=============================
Ensure that unprivileged _network_ namespaces are disabled, if they are not
required.
Note that unprivileged user/network namespaces are enabled by default in RHEL 8
but not in RHEL 7 and derivatives.
If sites need to have unprivileged _network_ namespaces enabled they should
consider the mitigation in [R 4], [R 5]
More information
================
There is the possibility that one of these vulnerabilities may be elevated to
'CRITICAL' if a public exploit is released which allows easy exploitation.
In general, the EGI SVG recommends disabling _network_ namespaces whenever
possible, as many vulnerabilities are only exploitable if network namespaces
are enabled.
TLP and URL
===========
** WHITE information - Unlimited distribution
- see https://go.egi.eu/tlp for distribution restrictions **
URL: https://advisories.egi.eu/Advisory-SVG-CVE-2020-25211
Minor updates may be made without re-distribution to the sites
Comments
========
Comments or questions should be sent to svg-rat at mailman.egi.eu
If you find or become aware of another vulnerability which is relevant to EGI
you may report it by e-mail to
report-vulnerability at egi.eu
the EGI Software Vulnerability Group will take a look according to the
procedure defined in [R 6]
Note that this is undergoing revision to fully handle vulnerabilities in the
EOSC-hub era.
References
==========
[R 1] https://access.redhat.com/errata/RHSA-2021:0003
[R 2] https://nvd.nist.gov/vuln/detail/CVE-2020-25211
[R 3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25211
[R 4] https://access.redhat.com/security/cve/CVE-2020-25211
[R 5] https://access.redhat.com/solutions/41278
[R 6] https://documents.egi.eu/public/ShowDocument?docid=3145
[R 7] https://access.redhat.com/security/cve/CVE-2020-29661
Credit
======
SVG was alerted to both the vulnerabilities specifically mentioned by Vincent
Brillault
Timeline
========
Yyyy-mm-dd [EGI-SVG-2021-CVE-2020-25211]
2021-01-04 SVG alerted to CVE-2020-25211 by Vincent Brillault
2021-01-04 Acknowledgement from the EGI SVG to the reporter
2021-01-04 Investigation of vulnerability and relevance to EGI carried out
2021-01-05 EGI SVG Risk Assessment completed
2021-01-06 Advisory sent to sites to mitigate CVE-2020-25211
2021-02-17 SVG alerted to CVE-2020-29661 by Vincent Brillault
2021-03-16 RedHat Kernel release which fixes various vulnerabilities, including
CVE-2020-25211, CVE-2020-29661
2021-03-22 Advisory/update issued as fix available for RHEL 7, CentOS 7, RHEL
8, CentOS 8 for at least 2 vulnerabilities.
2021-04-06 Advisory placed on the EGI SVG wiki
Context
=======
This advisory has been prepared as part of the effort to fulfil EGI SVG's
purpose "To minimize the risk to the EGI infrastructure arising from software
vulnerabilities"
The risk is that assessed by the group, according to the EGI SVG issue handling
procedure [R 6] in the context of how the software is used in the EGI
infrastructure. It is the opinion of the group, we do not guarantee it to be
correct. The risk may also be higher or lower in other deployments depending
on how the software is used.
-----------------------------
This advisory is subject to the Creative commons licence
https://creativecommons.org/licenses/by/4.0/ and the EGI https://www.egi.eu/
Software Vulnerability Group must be credited.
-----------------------------
Note that the SVG issue handling procedure is currently under review, to take
account of the increasing inhomogeneity of the EGI infrastructure and the
services in the EOSC-hub catalogue.
On behalf of the EGI SVG,