Secure Firewall Threat DefenseApplication · Cisco
CVE-2023-20246
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 Snort access control policies that could allow an unauthenticated, remote attacker to bypass the configured policies on an affected system. This vulnerability is due to a logic error that occurs when the access control policies are being populated. An attacker could exploit this vulnerability by establishing a connection to an affected device. A successful exploit could allow the attacker to bypass configured access control rules on the affected system.
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 · moderate confidenceA logic error in Snort's access control policy population mechanism allows an unauthenticated remote attacker to bypass configured access control rules. When policies are being loaded or populated, a flaw causes certain rules to not be properly enforced, enabling traffic that should be blocked to pass through unaffected systems.
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, <= 7.3.1.1
Ios XeOperating system
>= 17.12, < 17.12.2>= 3.0.0, < 3.1.57.0CVSS 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
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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.
-
Identify installed product and versionRun 'show version' on Cisco devices; run 'snort --version' for Snort. Compare the output to the affected version ranges: Firepower 7.0.0-7.3.1.1, IOS Xe 17.12 to before 17.12.2, Snort 3.0.0 to before 3.1.57.0Affected if The installed version falls within any of the affected ranges
-
Confirm access control policies are configuredCheck if any access control policies or ACLs are defined in the system. For Firepower/IOS Xe, use 'show access-list' or similar policy inspection commands. For Snort, check for configured rules in the snort.conf or related policy filesAffected if Access control policies or ACLs are present in the configuration
-
Verify policy loading status after startup or reloadAfter system boot, reload, or policy deployment, check the policy status. Look for indicators that policies have been fully loaded and are active. Some systems log policy population eventsAffected if Policies were recently loaded, deployed, or the system was restarted
-
Test policy enforcement with known blocked trafficGenerate test traffic that should be blocked by your configured rules (for example, traffic to a denied port or from a blocked source). Capture and verify whether the traffic is correctly blocked or unexpectedly passes throughAffected if Traffic that should be blocked by your access control rules is being allowed through
A user is affected if they run an affected version AND have configured access control policies that may not be properly enforced during or after policy loading events.
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 · scoped3.1.57.017.12.2
Apply Cisco's patches for affected products; verify that access control policies are correctly loaded and enforced after patching.
Snort >= 3.1.57.0, IOS Xe >= 17.12.2, Secure Firewall Threat Defense > 7.3.1.1
- 1. Identify the affected product (Secure Firewall Threat Defense, IOS Xe, or Snort) running on your system
- 2. For Snort: upgrade to version 3.1.57.0 or later
- 3. For IOS Xe: upgrade to version 17.12.2 or later
- 4. For Secure Firewall Threat Defense: upgrade to a version greater than 7.3.1.1 (check Cisco's release notes for the specific fixed release)
- 5. After upgrade, verify that access control policies are functioning correctly by testing network traffic against the configured rules
- 6. Review the Snort IPS policy to ensure all rules are loading properly post-upgrade
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20246 — 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-2023-20246 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