CVE-2021-1435 is a vulnerability in Cisco IOS XE
Published on March 24, 2021

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to inject arbitrary commands that can be executed as the root user. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a crafted request to the web UI of an affected device with arbitrary commands injected into a portion of the request. A successful exploit could allow the attacker to execute arbitrary commands as the root user.

Vendor Advisory NVD

Known Exploited Vulnerability

This Cisco IOS XE Web UI Command Injection Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Cisco IOS XE contains a command injection vulnerability in the web user interface that could allow a remote, authenticated attacker to inject commands that can be executed as the root user.

The following remediation steps are recommended / required by November 9, 2023: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vulnerability Analysis

CVE-2021-1435 can be exploited with network access, and requires user privileges. This vulnerability is considered to have a low attack complexity. It has an exploitability score of 1.2 out of four. The potential impact of an exploit of this vulnerability is considered to be very high.

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2021-1435 has been classified to as a Directory traversal vulnerability or weakness.

Products Associated with CVE-2021-1435

You can be notified by stack.watch whenever vulnerabilities like CVE-2021-1435 are published in these products:

Cisco IOS XE

What versions of IOS XE are vulnerable to CVE-2021-1435?