Vulnerability identifier: #VU56423

Vulnerability risk: Low

CVSSv3.1: 5.8 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34721

CWE-ID: CWE-78

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Cisco IOS XR
Operating systems & Components / Operating system
Cisco ASR 9000 Series Aggregation Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper input validation in the XML configuration manager of Cisco IOS XR Software. A local user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: 6.7.1 - 7.4

Cisco ASR 9000 Series Aggregation Services Routers: 6.7 - 7.4

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-cmd-inj-wbZKvPxc
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvx48002

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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