Improper Authorization in Cisco Virtualized Packet Core and Cisco StarOS - CVE-2021-1539
Published: June 2, 2021
Vulnerability identifier: #VU53746
CSH Severity: Medium
CVSS v4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-1539
CWE-ID: CWE-285
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to gain unauthorized access to the system.
The vulnerability exists in the authorization process of Cisco ASR 5000 Series Software (StarOS) due to incorrect authorization of non-interactive CLI commands. A remote authenticate user can bypass TACACS authorization by sending a crafted Secure Shell (SSH) request to an affected device and execute a certain CLI commands.
Successful exploitation of the vulnerability may result in unauthorized access to sensitive information or denial of service condition.
Affected software
Cisco Virtualized Packet Core
Cisco StarOS
Cisco StarOS
How to mitigate CVE-2021-1539
Install updates from vendor's website.
Cisco StarOS - addressed in versions 21.16.9, 21.17.10, 21.18.16, 21.19.n7, 21.20.8, 26.19.11