UBUNTU-CVE-2021-38173: Critical severity ubuntu/btrbk vulnerability
Btrbk before 0.31.2 allows command execution because of the mishandling of remote hosts filtering SSH commands using sshfilterbtrbk.sh in authorizedkeys.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/btrbkto a version that resolves this vulnerability.Fixed in 0.26.0-1ubuntu0.1~esm1 - Upgrade
Upgrade
ubuntu/btrbkto a version that resolves this vulnerability.Fixed in 0.27.1-1ubuntu0.1~esm1
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Deployments using Btrbk before 0.31.2 are affected when remote hosts are configured to filter SSH commands through ssh_filter_btrbk.sh in authorized_keys.
What does an attacker need to exploit it?
The issue is remotely exploitable without privileges or user interaction, as reflected by the AV:N/AC:L/PR:N/UI:N vector. Successful exploitation can result in command execution.
What should be done to remediate the issue?
Upgrade Btrbk to version 0.31.2 or later. The vulnerability is caused by mishandling of remote-host filtering in ssh_filter_btrbk.sh used from authorized_keys.