Catalyst Digital Building Series Switches FirmwareOperating system · Cisco
CVE-2022-20731
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 vulnerabilities that affect Cisco Catalyst Digital Building Series Switches and Cisco Catalyst Micro Switches could allow an attacker to execute persistent code at boot time or to permanently prevent the device from booting, resulting in a permanent denial of service (DoS) condition. For more information about these vulnerabilities, see the Details section of this advisory.
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 confidenceMultiple vulnerabilities in Cisco Catalyst Digital Building Series Switches and Cisco Catalyst Micro Switches allow an attacker to execute persistent code at boot time or permanently brick the device, causing a permanent denial of service. The vulnerabilities appear to be at the firmware/boot level, enabling malicious code to survive reboots or rendering the device unusable.
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
Catalyst Digital Building Series Switches FirmwareOperating system
<= 15.2\(7\)e
Ios RommonOperating system
all versionsCVSS 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
- Physical
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.
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Identify switch model and firmware versionConnect to the switch CLI and run 'show version' to display the firmware version, or access the switch web interface to view the device information pageAffected if The displayed firmware version is 15.2(7)e or earlier on Cisco Catalyst Digital Building Series Switches or Cisco Catalyst Micro Switches
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Check IOS Rommon versionAt the switch prompt, enter 'show rom-monitor' or during boot, press Break to enter Rommon mode and note the Rommon version displayedAffected if Any version of Cisco IOS Rommon is displayed (all versions are affected according to the CVE)
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Verify normal boot sequencePower cycle the device and observe the boot process for any unusual messages, delays, or unexpected prompts that deviate from the standard boot sequenceAffected if The device exhibits abnormal boot behavior such as unexpected boot loops, unusual prompts before the IOS prompt, or failure to reach the normal operating system prompt
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Check for persistent unauthorized codeAfter boot completes, run 'show running-config' and 'show startup-config' to compare configurations, then check for any unexpected files or scripts using 'dir flash:'Affected if Startup and running configurations differ unexpectedly, or unexpected files/scripts are present in flash memory that were not intentionally deployed
A user is affected if they have a Cisco Catalyst Digital Building Series Switch running firmware version 15.2(7)e or earlier, or any Rommon version on the affected switch models, particularly if abnormal boot behavior or unauthorized configurations are observed.
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.
From vendor dataApply Cisco firmware updates for the affected switch models once available; if devices are suspected to be compromised, perform a secure factory reset and verify firmware integrity before redeployment.
Fix this in Catalyst Digital Building Series Switches Firmware
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-20731 — 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-2022-20731 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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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
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