CVE Vulnerabilities

CVE-2021-1612

Improper Link Resolution Before File Access ('Link Following')

Published: Sep 23, 2021 | Modified: Sep 30, 2021
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS 2.x
6.6 MEDIUM
AV:L/AC:L/Au:N/C:N/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the Cisco IOS XE SD-WAN Software CLI could allow an authenticated, local attacker to overwrite arbitrary files on the local system. This vulnerability is due to improper access controls on files within the local file system. An attacker could exploit this vulnerability by placing a symbolic link in a specific location on the local file system. A successful exploit could allow the attacker to overwrite arbitrary files on an affected device.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Sd-wan Cisco * *

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References