Overview
Extended Security Maintenance gets an extension, Linux disk encryption and
authentication goes under the microscope and we cover security updates for
libgcrypt, the Linux kernel, Python, and more.
This week in Ubuntu Security Updates
20 unique CVEs addressed
[USN-5078-2] Squashfs-Tools vulnerabilities [01:02]
- 2 CVEs addressed in Xenial ESM (16.04 ESM), Bionic (18.04 LTS), Focal (20.04 LTS), Hirsute (21.04)
- Side-channel attacks against the various ElGamal implementations in
OpenPGP - https://eprint.iacr.org/2021/923 - researchers from IBM
Research Europe
- Patent free public key encryption scheme - popular in OpenPGP - 1 in 6
registered OpenPGP keys have an ElGamal subkey
- Various implementations of ElGamal are used in different OpenPGP
implementations - Go stdlib, Crypto++ and gcrypt
- libgcrypt has previously had other side-channel vulns found and was used
in the development of FLUSH+RELOAD attack against GnuPG
- This attack exploits the different configurations used in the various
implementations to use timing differences to be able to recover plaintext
- Fixed to remove support for smaller key lengths and add exponent blinding
(combining the exponent with randomness to avoid it being inferred by
timing analysis)
[USN-5071-2] Linux kernel (HWE) vulnerabilities [04:11]
- 5 CVEs addressed in Bionic (18.04 LTS)
- AMD nested virtualisation vulns (Episode 130, Episode 131)
- 2 other KVM vulns - UAF
- OOB write in joystick subsystem via a malicious
ioctl()
- requires a joystick device to be present
- snaps joystick interface is not auto-connected by default
[USN-5071-3] Linux kernel (Raspberry Pi) vulnerabilities
- 2 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS)
[USN-5082-1] Linux kernel (OEM) vulnerabilities
- 3 CVEs addressed in Focal (20.04 LTS)
- CAN BCM UAF (Episode 121), AMD nested virtualisation
[USN-5073-2] Linux kernel (GCP) vulnerabilities
- 5 CVEs addressed in Xenial ESM (16.04 ESM), Bionic (18.04 LTS)
[USN-5073-3] Linux kernel (Raspberry Pi) vulnerabilities
- 3 CVEs addressed in Bionic (18.04 LTS)
[USN-5079-3] curl vulnerabilities [06:34]
[USN-5081-1] Qt vulnerabilities [06:49]
- 2 CVEs addressed in Bionic (18.04 LTS)
- 2 issues in graphics / image handling
- crafted XBM trigger OOB read -> crash
- OOB write when rendering SVG or other crafted vector content
[USN-5083-1] Python vulnerabilities [07:22]
- 2 CVEs addressed in Trusty ESM (14.04 ESM), Xenial ESM (16.04 ESM)
- ReDOS - a malicious HTTP server which would send a crafted response for
BasicAuth which would cause high CPU usage in trying to match the header
value via a regex - fixed to use a simpler regex
- Malicious server could cause a client to hang even if the client had set
a timeout - server sends a ‘100 Continue’ response and the client would
sit there waiting to receive more input which would never arrive (since
server is malicious)
[USN-5084-1] LibTIFF vulnerability [08:32]
- 1 CVEs addressed in Focal (20.04 LTS)
- Buffer overflow via crafted TIFF file
[USN-5079-4] curl regression [08:42]
- 2 CVEs addressed in Trusty ESM (14.04 ESM), Xenial ESM (16.04 ESM)
- Mistake in backporting patch would cause STARTTLS to fail when used for
SMTP only - thanks for tuaris for metioning this on
https://ubuntuforums.org/showthread.php?t=2467177 but next time please
file a LP bug directly as you will get our attention much faster (and
more reliably)
Goings on in Ubuntu Security Community
Authenticated boot and disk encryption on Linux [09:28]
Ubuntu 14.04 and 16.04 ESM extended [14:16]
RELEASE |
RELEASE DATE |
END OF LIFE* |
Ubuntu 14.04 (Trusty Tahr) |
April 2014 |
April 2024(from April 2022) |
Ubuntu 16.04 (Xenial Xerus) |
April 2016 |
April 2026(from April 2024) |
Ubuntu 18.04 (Bionic Beaver) |
April 2018 |
April 2028(unchanged) |
Ubuntu 20.04 (Focal Fossa) |
April 2020 |
April 2030(unchanged) |
- Use extra time to plan upgrades
Hiring [15:48]
Linux Cryptography and Security Engineer
Security Engineer - Ubuntu
Security Product Manager
Get in contact