Secure Firewall Threat DefenseApplication · Cisco
CVE-2024-20330
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability in the Snort 2 and Snort 3 TCP and UDP detection engine of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause memory corruption, which could cause the Snort detection engine to restart unexpectedly. This vulnerability is due to improper memory management when the Snort detection engine processes specific TCP or UDP packets. An attacker could exploit this vulnerability by sending crafted TCP or UDP packets through a device that is inspecting traffic using the Snort detection engine. A successful exploit could allow the attacker to restart the Snort detection engine repeatedly, which could cause a denial of service (DoS) condition. The DoS condition impacts only the traffic through the device that is examined by the Snort detection engine. The device can still be managed over the network. Note: Once a memory block is corrupted, it cannot be cleared until the Cisco Firepower 2100 Series Appliance is manually reloaded. This means that the Snort detection engine could crash repeatedly, causing traffic that is processed by the Snort detection engine to be dropped until the device is manually reloaded.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThis vulnerability exists in the Snort detection engine of Cisco FTD on 2100 Series appliances. Attackers send specially crafted TCP/UDP packets that cause memory corruption during packet processing. Once memory is corrupted, the Snort engine crashes repeatedly until the device is manually reloaded, causing sustained denial of service for inspected traffic.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Secure Firewall Threat DefenseApplication
= 7.0.0.0= 7.0.0.1= 7.0.1= 7.0.1.1= 7.0.2= 7.0.2.1= 7.0.3= 7.0.4= 7.0.5= 7.0.6= 7.0.6.1= 7.0.6.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify the hardware modelRun 'show version' or check the device chassis to confirm it is a Cisco 2100 Series appliance (e.g., 2110, 2120, 2130, 2140)Affected if The device is not a 2100 Series appliance, then it is not affected by this specific CVE
-
Check the installed FTD versionRun 'show version' or 'show running-config | include version' to retrieve the Cisco Firepower Threat Defense software versionAffected if The FTD version matches any of the following: 7.0.0.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.0.2.1, 7.0.3, 7.0.4, 7.0.5, 7.0.6, 7.0.6.1, or 7.0.6.2
-
Verify Snort inspection is enabledCheck the FTD policy configuration via 'show snort/sfe/inspect' or the FMC/FP管理界面 to confirm the Snort detection engine is active for traffic inspectionAffected if Snort inspection is disabled or not applied to any security policy, then the vulnerability is not exploitable in the current configuration
-
Examine system logs for crash indicatorsReview 'show crashinfo', 'show logging', or the system message logs for Snort process crashes, memory corruption errors, or repeated reload eventsAffected if Recent logs show Snort engine crashes or unexpected device reloads without an identifiable cause, this may indicate exploitation
The environment is affected only if the device is a 2100 Series appliance running FTD version 7.0.0.0 through 7.0.6.2 with Snort inspection enabled.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedApply the Cisco FTD security update for CVE-2024-20330 when available. No workarounds exist; the device requires manual reload to clear corrupted memory blocks after exploitation.
Any FTD version higher than 7.0.1.1 that includes the fix for CVE-2024-20330 (contact Cisco for specific fixed version)
- Contact Cisco Firepower support or check the Cisco Firepower 2100 Series Appliance software download page to obtain the fixed FTD version for this vulnerability (CVE-2024-20330)
- Verify the current FTD version on the affected device using 'show version' command
- Upgrade the FTD software to the fixed version recommended by Cisco for this specific CVE
- After upgrade, verify Snort detection engine is running using 'show module snort' command
- If memory corruption has already occurred (Snort crashing repeatedly), perform a manual reload of the Cisco Firepower 2100 Series Appliance to clear the corrupted memory block
- After reload, confirm traffic is flowing normally through the Snort-inspected interfaces
- Monitor the device to ensure Snort detection engine remains stable
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,168.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-20330 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-20330 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data