Episode 193

Show Notes

Overview

The release of Ubuntu 23.04 Lunar Lobster is nigh so we take a look at some of the things the security team has been doing along the way, plus it’s our 6000th USN so we look back at the last 19 years of USNs whilst covering security updates for the Linux kernel, Emacs, Irssi, Sudo, Firefox and more.

This week in Ubuntu Security Updates

109 unique CVEs addressed

[USN-5998-1] Apache Log4j vulnerabilities (01:00)

4 CVEs addressed in Xenial ESM (16.04 ESM), Bionic (18.04 LTS), Focal (20.04 LTS)
A bunch of older vulnerabilities, some discovered in the wake of log4shell but not deemed as critical

[USN-6000-1] Linux kernel (BlueField) vulnerabilities (01:37)

23 CVEs addressed in Focal (20.04 LTS)
NVIDIA BlueField specific kernel (5.4)
Most high priority CVE UAF in Upper Level Protocol (mentioned in the last few episodes)
6000th USN published by the Ubuntu Security team - this one by Rodrigo Zaiden
Out of interest:
- USN-5000-1 - also a kernel USN in June 2021 (Steve Beattie)
- USN-4000-1 - corosync in May 2019 (Leo Barbosa)
- USN-3000-1 - kernel (utopic HWE backported to trusty) in June 2016 (John Johansen)
- USN-2000-1 - nova in October 2013 (Jamie Strandboge)
- USN-1000-1 - kernel again in October 2010 (Kees Cook)
- USN-1-1 - libpng again in October 2004 (Matt Zimmerman)

[USN-6003-1] Emacs vulnerability (05:03)

1 CVEs addressed in Xenial ESM (16.04 ESM)
- CVE-2023-28617
Similar to [USN-5955-1] Emacs vulnerability [00:50] from Episode 191 - again if used org-mode to output to a latex document which included other documents that had shell metacharacters in their filenames, could get code execution as the user running Emacs

[USN-6002-1] Irssi vulnerability (05:45)

1 CVEs addressed in Kinetic (22.10)
- CVE-2023-29132
IRC client - UAF when outputting a line which was not formatted whilst also outputting a line that was formatted - only likely to be able to be triggered by various scripts - was discovered after a recent update to GLib 2.75 which stopped using it’s own internal memory allocator and instead switched to regular malloc() / free() - would then trigger the memory checking of libc which detected this

[USN-6005-1] Sudo vulnerabilities (07:25)

2 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Jammy (22.04 LTS), Kinetic (22.10)
- CVE-2023-28487
- CVE-2023-28486
Failed to escape control characters in both the log output and sudoreplay (can be used to list or play back the commands executed in a sudo session) - and so could allow an attacker to get code execution as the user running sudoreplay by injecting terminal control characters

[USN-6010-1] Firefox vulnerabilities (08:45)

15 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS)
112.0 - one Linux specific vuln in particular around the handling of downloaded .desktop files - could allow an attacker to get code execution as the user running firefox - interesting to note that as a snap, firefox is confined by default and cannot execute arbitrary commands from the host system - can only use binaries from within the firefox snap itself or the user’s $HOME which makes exploitation of such an issue harder since less LOLBins to make use of

[USN-6011-1] Json-smart vulnerabilities (10:00)

2 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Jammy (22.04 LTS), Kinetic (22.10)
- CVE-2023-1370
- CVE-2021-31684
Small and fast JSON parser for Java - two similar issues, one in handling of unclosed quotes and the other in unclosed brackets - both could allow an attacker to DoS the application through crafted input

Goings on in Ubuntu Security Community

Preparing for the release of Ubuntu 23.04 (Lunar Lobster) (10:36)

Team has been busy finishing various items from the development roadmap for this cycle:
- SBOM specification
- improvements to how we distribute OVAL data
- evaluation of dbus-broker integration with AppArmor to possibly replace dbus-daemon in a future Ubuntu release
- Testing unprivileged user namespace restrictions via AppArmor
- io_uring mediation support in AppArmor
- Working with the snapd team on integrating dm-verity within snapd for improved integrity of snaps
- Usual maintenance items as well:
  - all the normal CVE patching
  - a heap of MIR security reviews
  - snap store reviews
  - AppArmor upstream project maintenance
- and more

Ubuntu Security Podcast on 2 weeks break

Alex on leave next week and the following week is the 23.10 start-of-cycle product roadmap sprint in Prague
Expect the podcast to be back the week ending 5th May