Title: EGI SVG 'ADVISORY' [TLP:WHITE] Up to CRITICAL risk
Linux kernel vulnerabilities [EGI-SVG-CVE-2023-1829]
Date: 2023-08-10
Updated: 2023-09-15
Affected software and risk
==========================
Up to CRITICAL risk vulnerabilities concerning the Linux kernel
Package : Linux kernel - affecting RHEL8 and RHEL7:--
CVE ID : CVE-2023-1829 CVSS score 7.4 [R 2]
CVE ID : CVE-2023-1281 CVSS score 7.8 [R 1]
These have the potential for local privilege escalation
Package : Linux kernel - affecting RHEL8 and RHEL9:--
CVE-ID : CVE-2023-2235 CVSS score 7.8 [R 3]
In cases where RH7 is affected RedHat has said they will NOT fix and
mitigation is thus advised instead.
Note that we consider these at least high risk
Actions required/recommended
============================
Sites are recommended to update relevant components as soon as possible
if updates are available for the distribution they install.
Note that RedHat is stating it will NOT provide updates for RH7.
For sites who cannot update, we recommend mitigation where possible.
Component installation information
==================================
Sites running RHEL should see [R 1], [R 2], [R 3], [R 4]
Sites running CentOS should also see [R 1], [R 2], [R 3], [R 4], [R 5]
Sites running Debian should see [R 6] and similar links
Sites running Ubuntu should see [R 7] and similar links
Sites running RockyLinux should see [R 8]
Sites running Almalinux should see [R 9]
Mitigation
==========
For CVE-2023-1281 and CVE-2023-1829 RedHat recommends disabling
module cls_tcindex as mitigation [R 1]
The recommendations on Linux namespaces and containers in [R 10]
may be followed to mitigate both CVE-2023-1281 and CVE-2023-1829.
More information
================
One group has claimed to to produce an exploit for CVE-2023-1829 is
available at [R 11], for this reason we consider this vulnerability
as potentially CRITICAL risk. However, this vulnerability does NOT
affect RHEL9. Hence, for RHEL8 and RHEL7 this vulnerability MAY
be critical, if the exploit works. (SVG has not tested it.)
Another relevant CVE is CVE-2023-2124 [R 4] CVSS score 7.0, which
affects RHEL7, RHEL8, and RHEL9. RedHat states as 'Moderate'.
There is the potential for Privilege escalation. By updating for
the previous vulnerabilities sites will have updated for this.
This advisory does cover multiple CVE's, with different Risks.
All these vulnerabilities are fixed via the same kernel release,
therefore we (the EGI SVG) thought it appropriate to issue one
advisory covering them all.
Hence this advisory is considered to be related to HIGH risk
vulnerabilities, plus a potentially CRITICAL one for RHEL7 and RHEL8.
Those vulnerabilities which affect RH7 are unlikely to be fixed for
Scientific Linux as Scientific Linux depends on RHEL7
TLP and URL
===========
** WHITE information - Unlimited distribution
- see https://go.egi.eu/tlp for
distribution restrictions **
URL: https://advisories.egi.eu/Advisory-SVG-CVE-2023-1829
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 99]
References
==========
[R 1] https://access.redhat.com/security/cve/CVE-2023-1281
[R 2] https://access.redhat.com/security/cve/CVE-2023-1829
[R 3] https://access.redhat.com/security/cve/CVE-2023-2235
[R 4] https://access.redhat.com/security/cve/CVE-2023-2124
[R 5] https://lists.centos.org/pipermail/centos-announce/
[R 6] https://security-tracker.debian.org/tracker/CVE-2023-1281
[R 7] https://ubuntu.com/security/CVE-2023-1281
[R 8] https://errata.build.resf.org/
[R 9] https://errata.almalinux.org/
[R 10] https://csirt.egi.eu/2022/10/19/linux-namespaces-and-containers/
[R 11] https://starlabs.sg/blog/2023/06-breaking-the-code-exploiting-and-examining-cve-2023-1829-in-cls_tcindex-classifier-vulnerability/
[R 99] https://documents.egi.eu/public/ShowDocument?docid=3867
Credit
======
SVG was alerted to these vulnerabilities by Mischa Salle
Timeline
========
Yyyy-mm-dd [EGI-SVG-CVE-2023-1281]
2023-08-08 SVG alerted to this issue by Mischa Salle
2023-08-08 EGI SVG Risk Assessment completed
2023-08-08 Advisory sent to sites
2023-09-15 Advisory placed on advisories.egi.eu
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 99] 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.
-----------------------------
On behalf of the EGI SVG,