Overview
Veritas Backup Exec contains a privilege escalation vulnerability due to the use of an OPENSSLDIR variable that specifies a location where an unprivileged Windows user can create files.
Description
CVE-2019-1552
Veritas Backup Exec includes an OpenSSL component that specifies an OPENSSLDIR variable as /usr/local/ssl/. On the Windows platform, this path is interpreted as C:\usr\local\ssl. Backup Exec contains a privileged service that uses this OpenSSL component. Because unprivileged Windows users can create subdirectories off of the system root, a user can create the appropriate path to a specially-crafted openssl.cnf file to achieve arbitrary code execution with SYSTEM privileges.
Impact
By placing a specially-crafted openssl.cnf in the C:\usr\local\ssl directory, an unprivileged user may be able to execute arbitrary code with SYSTEM privileges on a Windows system with the vulnerable Veritas software installed.
Solution
Apply an update
This vulnerability is addressed in Backup Exec 21.1 Hotfix 657517 (Engineering version 21.0.1200.1217) and Backup Exec 20.6 Hotfix 298543 (Engineering version 20.0.1188.2734).
Create a C:\usr\local\ssl directory
In cases where an update cannot be installed, this vulnerability can be mitigated by creating a C:\usr\local\ssl directory and restricting ACLs to prevent unprivileged users from being able to write to this location.
Acknowledgements
This vulnerability was reported by Will Dormann of the CERT/CC.
This document was written by Will Dormann.
Vendor Information
Other Information
| CVE IDs: | CVE-2020-36167 |
| Date Public: | 2020-12-23 |
| Date First Published: | 2020-12-23 |
| Date Last Updated: | 2021-01-06 18:37 UTC |
| Document Revision: | 3 |