StarosOperating system · Cisco
CVE-2023-20046
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 the key-based SSH authentication feature of Cisco StarOS Software could allow an authenticated, remote attacker to elevate privileges on an affected device. This vulnerability is due to insufficient validation of user-supplied credentials. An attacker could exploit this vulnerability by sending a valid low-privileged SSH key to an affected device from a host that has an IP address that is configured as the source for a high-privileged user account. A successful exploit could allow the attacker to log in to the affected device through SSH as a high-privileged user. There are workarounds that address this vulnerability.
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 privilege escalation vulnerability in Cisco StarOS Software's key-based SSH authentication. The flaw allows an attacker with a valid low-privileged SSH key to authenticate as a high-privileged user if the source IP matches that of a high-privileged account, due to insufficient credential validation.
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
StarosOperating system
< 21.22.14>= 21.23.0, < 21.23.31>= 21.25.0, < 21.25.15>= 21.26.0, < 21.26.17>= 21.27.0, < 21.27.6>= 21.28.0, < 21.28.3= 21.23.n= 21.24= 21.27.m= 21.28.mCVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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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Determine the installed StarOS versionExecute 'show version' command on the StarOS CLI to retrieve the running software versionAffected if The displayed version falls within any of the affected ranges: < 21.22.14; >= 21.23.0 and < 21.23.31; >= 21.25.0 and < 21.25.15; >= 21.26.0 and < 21.26.17; >= 21.27.0 and < 21.27.6; >= 21.28.0 and < 21.28.3; or is one of the specific versions 21.23.n, 21.24, 21.27.m, or 21.28.m for any values of n a
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Verify SSH key-based authentication is configuredExecute 'show ssh key' or 'show configuration | grep ssh' to check if SSH public key authentication is enabled on the systemAffected if SSH key-based authentication is configured and active for any user accounts
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Check for source IP restrictions on privileged accountsReview the SSH key configuration and account privileges using 'show configuration' or 'show user' commands to identify if any accounts have source IP binding restrictions configuredAffected if Privileged accounts (administrator or operator level) have source IP restrictions configured for their SSH keys, creating the condition where a lower-privileged user from the same source IP could attempt escalation
You are affected if your StarOS version is within the affected ranges AND you have SSH key authentication configured with privileged accounts that have source IP bindings, allowing a low-privileged key holder to potentially authenticate as a privileged user from that same source IP.
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 · scoped21.22.1421.23.3121.25.15
Apply Cisco's patch for CVE-2023-20046 to StarOS devices, or implement the available workarounds which involve reviewing SSH key configurations and potentially restricting source IP bindings for privileged accounts.
Upgrade to StarOS 21.26.17 (or the latest 21.x release available from Cisco)
- Identify the current StarOS version using 'show version' or 'show software' command
- Determine the appropriate upgrade path based on current version (21.22.x, 21.23.x, 21.25.x, or 21.26.x)
- Download the corresponding fixed release from Cisco (21.22.14, 21.23.31, 21.25.15, or 21.26.17) from the Cisco software download portal
- Upload the new StarOS image to the device using 'software add' or relevant file transfer method
- Reboot the device into the new image using 'reload' command
- Verify the upgrade was successful with 'show version' to confirm running the fixed release
- If using SSH key-based authentication, review user configurations to ensure no IP addresses are shared between high and low-privileged accounts
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Staros
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-20046 — 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-2023-20046 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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