CVE-2009-5140
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 · uneditedThe SIP implementation on the Linksys SPA2102 phone adapter provides hashed credentials in a response to an invalid authentication challenge, which makes it easier for remote attackers to obtain access via a brute-force attack, related to a "SIP Digest Leak" issue.
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 confidenceThe Linksys SPA2102 phone adapter's SIP implementation incorrectly returns hashed credentials when responding to an invalid authentication challenge, allowing attackers to capture these hashes and perform offline brute-force attacks to recover plaintext passwords.
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 dataall 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 SPA2102 device on your networkCheck network inventory, DHCP logs, or physically inspect devices for Linksys SPA2102 labels. Access the device web interface at its default IP (typically 192.168.0.1) and verify the model in the administration or status page.Affected if The device model is confirmed as Linksys SPA2102
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Verify SIP functionality is enabledLog into the SPA2102 web interface and navigate to the SIP settings or Line 1/Line 2 configuration pages. Check if SIP is enabled or if any phone lines are registered with SIP credentials.Affected if SIP is enabled and the device has SIP account credentials configured
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Confirm network accessibility of the deviceCheck firewall rules and network segmentation to determine if the SPA2102 device is reachable from networks outside your trusted internal segment. Test connectivity to port 5060 (SIP) from an untrusted interface.Affected if The device is accessible from untrusted networks or the internet on SIP ports (5060/UDP, 5061/TCP)
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Test for credential hash disclosure (optional/authorized testing only)Send a crafted SIP OPTIONS or INVITE request with invalid authentication to the device. Capture the response and inspect if it returns MD5 hashes of credentials rather than rejecting the request silently.Affected if The device responds with hashed credentials in an error response to invalid authentication challenges
If your environment contains a Linksys SPA2102 device with SIP enabled and accessible from your network, you are affected by CVE-2009-5140.
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 dataReplace or retire the end-of-life SPA2102 device, as no patched firmware may be available; if continued use is required, isolate the device on a restricted network segment with firewall rules limiting SIP exposure to trusted sources.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2009-5140 — 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-2009-5140 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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- 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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