A GNU Screen security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.
==========================================================================
Ubuntu Security Notice USN-4747-1
February 24, 2021
screen vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
Summary:
GNU Screen could be made to crash or run programs if it processed specially
crafted character sequences.
Software Description:
- screen: terminal multiplexer with VT100/ANSI terminal emulation
Details:
Felix Weinmann discovered that GNU Screen incorrectly handled certain
character sequences. A remote attacker could use this issue to cause GNU
Screen to crash, resulting in a denial of service, or possibly execute
arbitrary code.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 20.10:
screen 4.8.0-2ubuntu0.1
Ubuntu 20.04 LTS:
screen 4.8.0-1ubuntu0.1
Ubuntu 18.04 LTS:
screen 4.6.2-1ubuntu1.1
Ubuntu 16.04 LTS:
screen 4.3.1-2ubuntu0.1
In general, a standard system update will make all the necessary changes.
References:
https://usn.ubuntu.com/4747-1
CVE-2021-26937
Package Information:
https://launchpad.net/ubuntu/+source/screen/4.8.0-2ubuntu0.1
https://launchpad.net/ubuntu/+source/screen/4.8.0-1ubuntu0.1
https://launchpad.net/ubuntu/+source/screen/4.6.2-1ubuntu1.1
https://launchpad.net/ubuntu/+source/screen/4.3.1-2ubuntu0.1
