Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

[R1] Cisco Prime Collaboration Provisioning Restricted CLI Bypass Local Privilege Escalation

Medium

Synopsis

The Cisco Prime Collaboration Provisioning platform appears to provide a “walled” CLI (the CLI is similar to the one found on Cisco IOS) that protects the real Operating System from the user (Red Hat). This CLI is available through the terminal or SSH. However, a properly formatted “walled” CLI command available to users with the admin role (i.e. the default account) can bypass all protections and execute arbitrary commands as root. Two versions were tested and found vulnerable (9.0.0.23593 and 11.0.0.815). The second version (11.0.0.815) allows the root user to have access to a full/normal Red Hat bash terminal. However, all other user’s live in the walled-off CLI. Additionally, the first version (9.0.0.23593) has no option, as far as we could determine, to get access to a Red Hat bash terminal.

The admin user has access to the “show tech” command which will output a wide variety of diagnostic information. One of the options is to write the diagnostic information to disk. It was noticed that parsing extra quotes is not handled well and that “/bin/tar” is being executed via a system() call, and /bin/rm is being invoked as well. By appending a desired command after the quotes, it will get it executed four times. With a crafted command, an attacker could use this to control the entire box (including downloading additional software via wget).

Solution

Cisco has released Prime Collaboration Provisioning 11.1 which addresses this issue.

Disclosure Timeline

2015-12-23 - Issue discovered
2015-12-28 - Notified vendor via psirt@cisco.com
2015-12-28 - Vendor acknowledges receipt, assigns PSIRT-1265647782
2016-02-17 - Ping vendor for update
2016-02-18 - Vendor acks, loops in colleague handling case
2016-02-19 - Vendor indicates fixed in 11.1
2016-02-19 - Ask vendor if they are publishing advisory
2016-03-15 - Ping vendor for update
2016-03-15 - Vendor confirms advisory was posted on 2016-02-09

All information within TRA advisories is provided “as is”, without warranty of any kind, including the implied warranties of merchantability and fitness for a particular purpose, and with no guarantee of completeness, accuracy, or timeliness. Individuals and organizations are responsible for assessing the impact of any actual or potential security vulnerability.

Tenable takes product security very seriously. If you believe you have found a vulnerability in one of our products, we ask that you please work with us to quickly resolve it in order to protect customers. Tenable believes in responding quickly to such reports, maintaining communication with researchers, and providing a solution in short order.

For more details on submitting vulnerability information, please see our Vulnerability Reporting Guidelines page.

If you have questions or corrections about this advisory, please email advisories@tenable.com