Cisco NX-OS Software Python Parser Privilege Escalation Vulnerability

Update from August 25, 2021: Cisco found that this vulnerability was present in additional releases of Cisco NX-OS Software with the introduction of Python 3 support. For more information, see the Fixed Software [“#fs”] section of this advisory.

A vulnerability in the Python scripting subsystem of Cisco NX-OS Software could allow an authenticated, local attacker to escape the Python parser and issue arbitrary commands to elevate the attacker’s privilege level.

This vulnerability is due to insufficient sanitization of user-supplied parameters that are passed to certain Python functions in the scripting sandbox of the affected device. An attacker could exploit this vulnerability to escape the scripting sandbox and execute arbitrary commands to elevate the attacker’s privilege level.

To exploit this vulnerability, the attacker must have local access and be authenticated to the targeted device with administrative or Python execution privileges. These requirements could limit the possibility of a successful exploit.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-pyth-escal [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-pyth-escal”]