Bareos's negative command ACLs can be circumvented by abbreviating commands
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.8epss 0.5%
exploitation probability
0.5%top 58% of all CVEs
observed exploitation
nono source reports it
Bareos is open source software for backup, archiving, and recovery of data for operating systems. When a command ACL is in place and a user executes a command in bconsole using an abbreviation (i.e. "w" for "whoami") the ACL check did not apply to the full form (i.e. "whoami") but to the abbreviated form (i.e. "w"). If the command ACL is configured with negative ACL that should forbid using the "whoami" command, you could still use "w" or "who" as a command successfully. Fixes for the problem are shipped in Bareos versions 23.0.4, 22.1.6 and 21.1.11. If only positive command ACLs are used without any negation, the problem does not occur.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
bareos · bareos