CVE-2021-1145: cisco cisco asr 5000 series software UNIX Symbolic Link (Symlink) Following

Vulnerability summary

CVE-2021-1145 is a medium (CVSS 6.5) UNIX Symbolic Link (Symlink) Following vulnerability in cisco cisco asr 5000 series software. EPSS estimates a 1.29% chance of exploitation in the next 30 days, higher than 69.7% of scored vulnerabilities.

Timeline

1. 13-01-2021
   PublishedVulnerability first disclosed.
2. 12-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in the Secure FTP (SFTP) of Cisco StarOS for Cisco ASR 5000 Series Routers could allow an authenticated, remote attacker to read arbitrary files on an affected device. To exploit this vulnerability, the attacker would need to have valid credentials on the affected device. The vulnerability is due to insecure handling of symbolic links. An attacker could exploit this vulnerability by sending a crafted SFTP command to an affected device. A successful exploit could allow the attacker to read arbitrary files on the 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.