MNDT-2021-0008
BeyondTrust Privilege Management for Windows contains a local privilege escalation vulnerability prior to version 21.6
Impact
High - Exploiting the vulnerability will give a local unprivileged attacker SYSTEM level privileges.
Exploitability
Medium - Any authenticated local user can exploit the vulnerability and an exploit is trivial to produce.
CVE Reference
CVE-2021-42254
Technical Details
The installation of the agent uses the Windows Installer framework and an MSI file is cached in c:\windows\installer. An unprivileged user can trigger a repair operation, either by using the Windows Installer API or by running "msiexec.exe /fa c:\windows\installer\[XXXXX].msi".
Running a repair operation will trigger a number of file operations in the %TEMP% folder of the user triggering the repair. Some of these operations will be performed from a SYSTEM context (started via the Windows Installer service), including the execution of temporary files.
Resolution
The issue was fixed in version 21.6; update to this version to address the vulnerability.
Discovery Credits
- Ronnie Salomonsen, Mandiant
Disclosure Timeline
- 11-Oct-2021 - Issue reported to BeyondTrust
- 15-Oct-2021 - Issue confirmed by BeyondTrust and a fix scheduled for November 4.
- 4-Nov-2021 - Patched version released by BeyondTrust