Ios XeOperating system · Cisco
CVE-2023-20082
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 Cisco IOS XE Software for Cisco Catalyst 9300 Series Switches could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to the device to execute persistent code at boot time and break the chain of trust. This vulnerability is due to errors that occur when retrieving the public release key that is used for image signature verification. An attacker could exploit this vulnerability by modifying specific variables in the Serial Peripheral Interface (SPI) flash memory of an affected device. A successful exploit could allow the attacker to execute persistent code on the underlying operating system. Note: In Cisco IOS XE Software releases 16.11.1 and later, the complexity of an attack using this vulnerability is high. However, an attacker with level-15 privileges could easily downgrade the Cisco IOS XE Software on a device to a release that would lower the attack complexity.
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 is a vulnerability in Cisco IOS XE Software's image signature verification on Catalyst 9300 switches. Attackers with physical access or level-15 privileges can modify specific variables in SPI flash memory to inject persistent code that executes at boot time, bypassing the secure boot chain of trust.
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
Ios XeOperating system
< 17.3.7>= 17.4, < 17.6.5= 17.7CVSS 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.
-
Identify the IOS XE versionUse 'show version' command to display the running Cisco IOS XE software versionAffected if The version is less than 17.3.7, OR between 17.4 and 17.6.5 inclusive, OR exactly 17.7
-
Confirm device is a Catalyst 9300 modelUse 'show version' or 'show inventory' command to identify the hardware modelAffected if The device is a Catalyst 9300 series switch running the affected IOS XE versions
-
Check for level-15 privilege accountsUse 'show running-config | include username' and 'show privilege' to enumerate user accounts and current privilege levelAffected if Unauthorized level-15 accounts exist or unexpected privilege escalation has occurred
-
Verify secure boot statusUse 'show secure-boot' command if available on the device to check secure boot chain integrityAffected if Secure boot verification reports failure or is disabled
The device is affected if it runs Cisco IOS XE on a Catalyst 9300 with a version in the < 17.3.7, 17.4 to 17.6.5, or 17.7 range AND an attacker has physical access or has obtained level-15 privileges.
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 · scoped17.3.717.6.5
Apply the latest Cisco IOS XE Software update; restrict physical access to devices; monitor for unauthorized level-15 privilege escalation that could enable software downgrade to simplify exploitation.
Upgrade to Cisco IOS XE 17.3.7 or later (for <17.3.7), 17.6.5 or later (for >=17.4,<17.6.5), or 17.8 or later (for 17.7)
- 1. Identify the current Cisco IOS XE Software version running on the affected Catalyst 9300 Series Switch using 'show version' command
- 2. Determine if the current version is within an affected range: < 17.3.7, >= 17.4 and < 17.6.5, or exactly 17.7
- 3. Access Cisco Software Downloads (software.cisco.com) or use the Cisco IOS XE Software Upgrade Planner to obtain the fixed release
- 4. Download the appropriate fixed IOS XE image (17.3.7 or later for <17.3.7; 17.6.5 or later for >=17.4 and <17.6.5; 17.8 or later for 17.7)
- 5. Review Cisco release notes for any specific migration instructions or prerequisites
- 6. Back up the current device configuration using 'copy running-config startup-config' or TFTP/FTP export
- 7. Upload the new IOS XE image to the device's flash memory
- 8. Configure boot variable to point to the new image: 'boot system flash:<path-to-new-image>'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 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 $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20082 — 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-2023-20082 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