Vulnerability identifier: #VU56429

Vulnerability 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

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
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

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

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

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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.