SB2021060213 - Authorization bypass in Cisco ASR 5000 Series Software
Published: June 2, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Improper Authorization (CVE-ID: CVE-2021-1539)
CWE-ID: CWE-285 - Improper Authorization
CVSSv4: 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/E:U/U:Green
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.
2) Improper Authorization (CVE-ID: CVE-2021-1540)
CWE-ID: CWE-285 - Improper Authorization
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote user to gain unauthorized access to the system.
The vulnerability exists due to incorrect authorization of non-interactive CLI commands in the authorization process of Cisco ASR 5000 Series Software (StarOS). A remote authenticated user can send a specially crafted SSH request to an affected device, bypass the nocli option and execute certain CLI commands.
Remediation
Install update from vendor's website.