CVE-2018-0243
mediumpriority · track · 23EPSS 0.012 · 67 %ileEUUSEPSS · scored 2026-10-28
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Secure Firewall Threat Defense (FTD) Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
- cisco secure firewall threat defense< 6.2.3nvdUScpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- cisco-sa-20180418-fssCisco Firepower System Software Server Message Block File Policy Bypass Vulnerability2018-04-18csaf · cisco_csafUS
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. There are no workarounds that address this vulnerability.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-fsscnnvd
- https://www.securityfocus.com/bid/103943cnnvd
- http://www.securityfocus.com/bid/103943enisa_euvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-fssenisa_euvd
- http://www.securityfocus.com/bid/103943Third Party AdvisoryVDB Entrynvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-fssVendor Advisorynvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan