A vulnerability in the Remote Package Manager (RPM) subsystem of Cisco NX-OS Software could allow an authenticated, local attacker with administrator credentials to leverage a time-of-check, time-of-use (TOCTOU) race condition to corrupt local variables, which could lead to arbitrary command injection.
The vulnerability is due to the lack of a proper locking mechanism on critical variables that need to stay static until used. An attacker could exploit this vulnerability by authenticating to an affected device and issuing a set of RPM-related CLI commands. A successful exploit could allow the attacker to perform arbitrary command injection. The attacker would need administrator credentials for the targeted device.
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-rpm-injec [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-rpm-injec”]