Vulnerability identifier: #VU53747

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1540

CWE-ID: CWE-285

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco ASR 5000 Series
Hardware solutions / Firmware
Cisco Virtualized Packet Core
Client/Desktop applications / Virtualization software
Cisco StarOS
Operating systems & Components / Operating system

Vendor: Cisco Systems, Inc

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco ASR 5000 Series: All versions

Cisco Virtualized Packet Core: All versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr5k-autho-bypass-mJDF5S7n
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvv33622

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.