Cisco Enterprise NFV Infrastructure Software Denial of Service Vulnerability

Vulnerability

A denial of service (DoS) vulnerability exists in the user management functionality of Cisco Enterprise NFV Infrastructure Software (NFVIS). The flaw is due to insufficient validation of user-provided input. An authenticated attacker with highly privileged credentials can exploit this by performing a specific sequence of user management operations, leading to permanent interference with the underlying operating system. Affected versions are those before the fixed releases indicated in the referenced Cisco Security Advisory [1].

Exploitation

To exploit the vulnerability, an attacker must already have a highly privileged user account on an affected Cisco NFVIS system. No additional network position beyond remote access is required. The attacker then executes a sequence of specific user management operations that trigger the input validation flaw, causing the underlying OS to malfunction.

Impact

Successful exploitation results in a permanent denial of service (DoS) condition on the affected NFVIS system. The functionality is degraded to the point that the system can no longer operate normally, potentially requiring full re-imaging or replacement of the appliance.

Mitigation

Cisco has released fixed software versions to address this vulnerability. Customers should consult the Cisco bug ID(s) referenced in the advisory at the top of the security advisory page to identify the fixed releases [1]. Only authenticated and privileged users can exploit this flaw, so limiting access to trusted administrators is a necessary but not sufficient control. No workarounds are available.