Improper Neutralization of Argument Delimiters in a Command in Cisco IOS XR Software

Published: 2021-09-09

Risk	Medium
Patch available	YES
Number of vulnerabilities	1
CVE-ID	CVE-2021-34718
CWE-ID	CWE-88
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Cisco IOS XR Operating systems & Components / Operating system ASR9K-PX Hardware solutions / Firmware IOSXRWBD Hardware solutions / Firmware NCS5500 Hardware solutions / Firmware CRS-PX Hardware solutions / Firmware XRV9K Hardware solutions / Firmware NCS560 Hardware solutions / Firmware
Vendor	Cisco Systems, Inc

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Improper Neutralization of Argument Delimiters in a Command

EUVDB-ID: #VU56429

Risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34718

CWE-ID: CWE-88 - Argument Injection or Modification

Exploit availability: No

Description

The vulnerability allows a remote attacker to overwrite and read arbitrary files.

The vulnerability exists due to improper input validation in the SSH Server process. A remote authenticated attacker can specify Secure Copy Protocol (SCP) parameters when authenticating to a device and retrieve and upload files on a target device.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: 6.2.3 - 7.2.2

ASR9K-PX: All versions

IOSXRWBD: All versions

NCS5500: All versions

CRS-PX: All versions

XRV9K: All versions

NCS560: All versions

External links

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-scp-inject-QwZOCv2

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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