CVE-2019-18863
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 key length vulnerability in the implementation of the SRTP 128-bit key on Mitel 6800 and 6900 SIP series phones, versions 5.1.0.2051 SP2 and earlier, could allow an attacker to launch a man-in-the-middle attack when SRTP is used in a call. A successful exploit may allow the attacker to intercept sensitive information.
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 confidenceMitel 6800 and 6900 SIP phones running firmware 5.1.0.2051 SP2 and earlier contain a key length vulnerability in the SRTP 128-bit key implementation. The vulnerability allows a man-in-the-middle attacker to potentially recover encryption keys and intercept sensitive call content when SRTP is used, due to insufficient key strength or predictable key generation in the firmware implementation.
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< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051< 5.1.0.2051= 5.1.0.2051CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
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 the Mitel phone modelLocate the model number on the physical device label or check the device web interface or admin menu for the exact model designation (6863i, 6865i, 6867i, 6869i, 6873i, 6920, 6930, or 6940)Affected if Model is one of: 6863i, 6865i, 6867i, 6869i, 6873i, 6920, 6930, or 6940
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Check the installed firmware versionAccess the phone web interface, admin menu, or status screen and record the firmware version numberAffected if Firmware version is less than 5.1.0.2051 or equals exactly 5.1.0.2051
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Confirm SRTP is enabledCheck the phone SIP or security settings via the web interface or admin menu for SRTP (Secure Real-time Transport Protocol) configuration statusAffected if SRTP is enabled and configured for call encryption
The phone is affected if it is an affected model (6863i/6865i/6867i/6869i/6873i/6920/6930/6940) running firmware 5.1.0.2051 or earlier AND SRTP is enabled for calls.
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 data5.1.0.2051
Update Mitel 6800/6900 SIP phone firmware to a version beyond 5.1.0.2051 SP2. If immediate patching is not possible, ensure calls traverse trusted networks only and verify SRTP key exchange is functioning correctly.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-18863 — 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-2019-18863 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
- No weaponised exploit code, or anything meant to cause harm
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