Privilege escalation in Cisco IOS XR Software

Published: 2021-09-09

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-34721 CVE-2021-34722
CWE-ID	CWE-78
Exploitation vector	Local
Public exploit	N/A
Vulnerable software Subscribe	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

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) OS Command Injection

EUVDB-ID: #VU56423

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 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Exploit availability: No

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

External links

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

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.

2) OS Command Injection

EUVDB-ID: #VU56427

Risk: Medium