dbcve.org
Secure Firewall Threat DefenseApplication · Cisco

CVE-2022-20922

MEDIUM · 6.5 CVSS v3.1 Published 2022-11-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to improper management of system resources when the Snort detection engine is processing SMB2 traffic. An attacker could exploit these vulnerabilities by sending a high rate of certain types of SMB2 packets through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process, resulting in a DoS condition. Note: When the snort preserve-connection option is enabled for the Snort detection engine, a successful exploit could also allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network. The snort preserve-connection setting is enabled by default. See the Details ["#details"] section of this advisory for more information. Note: Only products that have Snort 3 configured are affected. Products that are configured with Snort 2 are not affected.

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 confidence

Vulnerabilities in the Snort 3 detection engine's SMB2 processor on Cisco products allow an unauthenticated remote attacker to send high-rate SMB2 packets and trigger Snort process reloads, causing denial of service. When the snort preserve-connection option is enabled (default), exploitation can also bypass configured security policies.

MitigationApply Cisco-provided software updates for affected products; consider disabling snort preserve-connection if supported as a temporary mitigation while planning the update.

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
Affected:= 7.1.0= 7.1.0.1= 7.1.0.2= 7.2.0= 7.2.0.1
Umbrella Virtual ApplianceApplication
Affected:= 1.5.4= 1.5.5= 1.5.6= 2.0.0= 2.0.2= 2.0.3= 2.1.0= 2.1.2= 2.1.4= 2.1.5= 2.2= 2.2.1
Cyber VisionApplication
Affected:= 3.0.0= 3.0.1= 3.0.2= 3.0.3= 3.0.5= 3.0.6= 3.1.0= 3.1.1= 3.1.2= 3.2.0= 3.2.1= 3.2.2

CVSS 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
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify product and version
    Use the system CLI or admin interface to determine the installed Cisco product name and exact software version (e.g., show version, system info)
    Affected if The product is Cisco Firepower Threat Defense, Cisco Umbrella Virtual Appliance, or Cisco Cyber Vision AND the version matches exactly one of: 7.1.0, 7.1.0.1, 7.1.0.2, 7.2.0, 7.2.0.1 (FTD); 1.5.4 through 2.2.1 (Umbrella VA); 3.0.0 through 3.2.2 (Cyber Vision)
  2. Confirm Snort 3 is active
    Verify that the system is running Snort 3 as its intrusion detection/prevention engine (check process list, service status, or snort -V output)
    Affected if Snort 3 is the active detection engine - the vulnerability exists specifically in Snort 3's SMB2 processor
  3. Verify SMB2 traffic inspection is enabled
    Check the Snort or firewall configuration for SMB2 protocol inspection rules or preprocessor settings (look for SMB2-related inspection, file policy, or protocol decode settings)
    Affected if SMB2 inspection is enabled - the flaw is triggered when the SMB2 processor processes incoming packets
  4. Check preserve-connection setting
    Examine the Snort configuration for the preserve-connection option (typically in snort.conf, the setting is 'config preserve-connection' or similar)
    Affected if preserve-connection is enabled (this is the default) - exploitation can bypass configured security policies only when this setting is on

You are affected if you run any of the listed product versions AND have Snort 3 active with SMB2 inspection enabled, especially with preserve-connection at its default enabled state.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply Cisco-provided software updates for affected products; consider disabling snort preserve-connection if supported as a temporary mitigation while planning the update.

Recommended fix Moderate confidence

Upgrade to releases after 7.2.0 for FTD; after 2.0.0 for Umbrella VA; after 3.0.3 for Cyber Vision

  1. 1. Identify the exact Cisco product and current version running (Firepower Threat Defense, Umbrella Virtual Appliance, or Cyber Vision)
  2. 2. Confirm Snort 3 is configured (only Snort 3 configurations are affected; Snort 2 is not vulnerable)
  3. 3. For Firepower Threat Defense: Upgrade to a release later than 7.2.0 (Cisco FTD releases after 7.2.0 contain the fix)
  4. 4. For Umbrella Virtual Appliance: Upgrade to a release later than 2.0.0
  5. 5. For Cyber Vision: Upgrade to a release later than 3.0.3
  6. 6. After upgrade, verify the Snort detection engine is functioning properly and policies are being enforced
  7. 7. Optionally, consider disabling snort preserve-connection if not needed (this limits bypass to DoS only, but does not fix the underlying vulnerability)
Caveat Upgrading major versions may introduce configuration or compatibility changes; test in non-production environment first

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
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-20922 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-20922 in production — separate from our analysis above.

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.

What this is

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.

What belongs here
  • 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