Cisco Security Advisory
Cisco Firepower Threat Defense Software Vulnerability Database with Snort Detection Engine Security Policy Bypass and Denial of Service Issue
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An issue with a Cisco Vulnerability Database (VDB) release for Cisco Firepower Threat Defense (FTD) Software could cause the Snort detection engine to restart unexpectedly when inspecting traffic. While the Snort detection engine is restarting, traffic could bypass Snort inspection or be dropped, depending on the device configuration. For more information, see the Details section of this advisory.
The Snort 2 and Snort 3 detection engines are both affected. The Snort detection engine will restart automatically. No manual intervention is required.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-vdb-snort-djj4cnbRThis advisory is part of the October 2024 release of the Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: October 2024 Semiannual Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.
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Vulnerable Products
This issue affects Cisco FTD Software if it is running Cisco VDB Release 396.
Determine the Cisco VDB Release
To determine which Cisco VDB release a Cisco FTD device is running, use the show version CLI command, as shown in the following example:
FTD> show version
-------------[ ftd-fmc2-mgmt ]---------------------
Model : Cisco Firepower Threat Defense for VMware (75) Version 7.2.8 (Build 25)
UUID : a0ed2102-6a3e-11ef-b9a6-b8830d51972b
LSP version : lsp-rel-20240930-1858
VDB version : 396
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FTD>View the VDB version line. If the release is 396, the issue that is described in this advisory is present. If any other release is listed, the issue that is described in this advisory is not present.
To view the Cisco VDB release in the Cisco Secure Firewall Management Center (FMC) Software, formerly Firepower Management Center, GUI, choose Help > About.
Products Confirmed Not Vulnerable
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this issue.
Cisco has confirmed that this vulnerability does not affect the following products:
- Cisco Adaptive Security Appliance (ASA) Software
- Cisco FMC Software
- Open Source Snort 2
- Open Source Snort 3
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The following Cisco FTD Software Snort detection engine configuration parameters govern how traffic is handled if the Snort process restarts:
- Snort Fail Open
- snort preserve-connection
For additional information, see the Snort Restart Traffic Behavior section of the Firepower Management Center Configuration Guide or the Managing Firewall Threat Defense with Cloud-delivered Firewall Management Center in Cisco Defense Orchestrator guide.
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There are no workarounds that address this issue.
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When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
Fixed Releases
At the time of publication, Cisco FTD Software contained the fix for this issue if it was running Cisco VDB Release 397 or later. Cisco VDB Release 396 has been removed from the Cisco Software Download Center.
See the Details section in the bug ID(s) at the top of the advisory for the most complete and current information.
For more information on upgrading the Cisco VDB, see the following resources:
- The Update the Vulnerability Database (VDB) section of the Firepower Management Center Configuration Guide
- The Updating System Databases section of the Cisco Firepower Threat Defense Configuration Guide for Firepower Device Manager
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
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The Cisco PSIRT is not aware of any public announcements or malicious use of the issue that is described in this advisory.
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This issue was found during the resolution of a Cisco TAC support case.
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Version Description Section Status Date 1.0 Initial public release. - Final 2024-OCT-23
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