SnortApplication · Cisco
CVE-2024-20342
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 · uneditedMultiple Cisco products are affected by a vulnerability in the rate filtering feature of the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured rate limiting filter. This vulnerability is due to an incorrect connection count comparison. An attacker could exploit this vulnerability by sending traffic through an affected device at a rate that exceeds a configured rate filter. A successful exploit could allow the attacker to successfully bypass the rate filter. This could allow unintended traffic to enter the network protected by the affected device.
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 rate filtering feature of Cisco's Snort detection engine. An incorrect connection count comparison allows an unauthenticated remote attacker to bypass configured rate limits by sending traffic that exceeds the configured threshold, permitting unintended traffic to enter the protected network.
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
SnortApplication
>= 3.0.0.0, < 3.1.74.0
Secure Firewall Threat DefenseApplication
< 7.0.6.2>= 7.2.0, < 7.2.6>= 7.4.0, < 7.4.2= 7.1.0= 7.3.0CVSS 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
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
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.
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Identify Snort software versionRun 'snort --version' or check the Snort package/version file installed on the systemAffected if The installed version is >= 3.0.0.0 and < 3.1.74.0
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Identify Firepower Threat Defense versionRun 'show version' or check the FTD version via the management interfaceAffected if The FTD version is < 7.0.6.2, or >= 7.2.0 and < 7.2.6, or >= 7.4.0 and < 7.4.2, or equals 7.1.0 or 7.3.0
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Confirm rate filtering is configuredInspect Snort configuration files (snort.conf) or rule files for 'rate_filter' or 'threshold' directives that define rate-based detectionAffected if Rate filtering rules are defined in the Snort configuration and actively loaded
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Verify rate filter is actively appliedCheck the active Snort policy or rule configuration via 'snort -c <config> --list-plugins' or management interface to confirm rate_filter rules are enabledAffected if Rate filtering is enabled and loaded into the active Snort detection policy
You are affected if your Snort version is 3.0.0.0 through 3.1.73.x, or your Firepower FTD version falls within the listed vulnerable ranges, AND you have rate filtering rules configured and active in your Snort policy.
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 · scoped3.1.74.07.0.6.27.2.6
Apply Cisco's vendor patches for affected products. As a temporary measure, review and tighten rate filter configurations and monitor for anomalous traffic patterns.
Snort: 3.1.74.0+ | FTD: 7.0.6.2+, 7.2.6+, or 7.4.2+ (avoid 7.1.0)
- For Snort users: Upgrade to Snort version 3.1.74.0 or later
- For Firepower Threat Defense Software users on 7.0.x branch: Upgrade to version 7.0.6.2 or later
- For Firepower Threat Defense Software users on 7.2.x branch: Upgrade to version 7.2.6 or later
- For Firepower Threat Defense Software users on 7.4.x branch: Upgrade to version 7.4.2 or later
- After upgrading, verify the rate filtering feature is functioning correctly with expected traffic
- Test that rate limiting filters are properly blocking traffic that exceeds the configured threshold
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Snort
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-20342 — 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-2024-20342 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
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- Version or environment caveats, and links to real fixes
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