CVE-2021-1612: cisco cisco ios xe sd-wan software UNIX Symbolic Link (Symlink) Following

Vulnerability summary

CVE-2021-1612 is a high (CVSS 7.1) UNIX Symbolic Link (Symlink) Following vulnerability in cisco cisco ios xe sd-wan software. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.2% of scored vulnerabilities.

Timeline

1. 23-09-2021
   PublishedVulnerability first disclosed.
2. 07-11-2024
   Last modifiedVulnerability information updated.

Description

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.

• CWE-61UNIX Symbolic Link (Symlink) FollowingThe product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
• CWE-59Improper Link Resolution Before File Access ('Link Following')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.