Cisco Secure Firewall Threat Defense
CVE-2018-0243
A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured file action policy that is intended to drop the Server Message Block Version 2 (SMB2) and SMB Version 3 (SMB3) protocols if malware is detected. The vulnerability is due to incorrect detection of an SMB2 or SMB3 file based on the total file length. An attacker could exploit this vulnerability by sending a crafted SMB2 or SMB3 transfer request through the targeted device. An exploit could allow the attacker to pass SMB2 or SMB3 files that could be malware even though the device is configured to block them. This vulnerability does not exist for SMB Version 1 (SMB1) files. This vulnerability affects Cisco Firepower System Software when one or more file action policies are configured, on software releases prior to 6.2.3. Cisco Bug IDs: CSCvg68807.
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 remotely, over a network, without a login, and without anyone at your company clicking anything.
What to do
- 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.
- 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
- 5.8 (v3.0)
- Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N- Weakness
- CWE-693
- Assigned by
- psirt@cisco.com
Dates
- Published
- 2018-04-19
- Last modified
- 2026-08-11
- Sources
- NVD
Affected products
- Cisco Secure Firewall Threat Defense- 6.2.3
As listed in the NVD configuration data. Not a statement about your estate.