6.0Medium

Cisco Secure Firewall Threat Defense

CVE-2021-1256

A vulnerability in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to overwrite files on the file system of an affected device by using directory traversal techniques. A successful exploit could cause system instability if important system files are overwritten. This vulnerability is due to insufficient validation of user input for the file path in a specific CLI command. An attacker could exploit this vulnerability by logging in to a targeted device and issuing a specific CLI command with crafted user input. A successful exploit could allow the attacker to overwrite arbitrary files on the file system of the affected device. The attacker would need valid user credentials on the device.

What this means for your business

  • It affects Cisco Secure Firewall Threat Defense. It matters if your company, or a supplier that handles your data, runs it.
  • An attacker can use it only with access to the machine itself, with an administrator login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 41% of all known flaws.

What to do

  1. 1Check whether your company or your suppliers run Cisco Secure Firewall Threat Defense, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
6.0 (v3.1)
Vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
Weakness
CWE-552
Assigned by
psirt@cisco.com

Dates

Published
2021-04-29
Last modified
2026-08-11
Sources
NVD

Affected products

  • Cisco Secure Firewall Threat Defense- 6.4.0, 6.6.0 - 6.6.4

As listed in the NVD configuration data. Not a statement about your estate.

References