Cisco Secure Firewall FMC/FTD sftunnel Path Traversal: Auth File Write
CVE-2026-20018 Published on March 4, 2026

Cisco Firepower Management Center Software and Firepower Threat Defense Path Traversal Vulnerability
A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. This vulnerability is due to insufficient validation of the directory path during file synchronization. An attacker could exploit this vulnerability by crafting a directory path outside of the expected file location. A successful exploit could allow the attacker to create or replace any file on the underlying operating system.

NVD

Vulnerability Analysis

CVE-2026-20018 is exploitable with network access, and requires user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity and availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
HIGH
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Path Traversal: 'dir/../../filename'

The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize multiple internal "../" sequences that can resolve to a location that is outside of that directory.


Products Associated with CVE-2026-20018

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Cisco Secure Firewall Management Center
 

Affected Versions

Cisco Secure Firewall Management Center (FMC): Cisco Secure Firewall Threat Defense (FTD) Software: