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Ip Phone 8800 SeriesApplication · Cisco

CVE-2017-6656

MEDIUM · 5.9 CVSS v3.0 Published 2017-06-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
A vulnerability in Session Initiation Protocol (SIP) call handling of Cisco IP Phone 8800 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the SIP process unexpectedly restarting. All active phone calls are dropped as the SIP process restarts. More Information: CSCvc29353. Known Affected Releases: 11.0(0.1). Known Fixed Releases: 11.0(0)MP2.153 11.0(0)MP2.62.

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 confidence

A vulnerability in the Session Initiation Protocol (SIP) call handling of Cisco IP Phone 8800 Series devices allows an unauthenticated, remote attacker to cause a denial of service by triggering an unexpected restart of the SIP process, which drops all active phone calls.

MitigationUpgrade Cisco IP Phone 8800 Series devices to fixed release 11.0(0)MP2.153 or 11.0(0)MP2.62 or later to remediate this vulnerability.

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
Ip Phone 8800 SeriesApplication
Affected:= 11.0\(0.1\)

CVSS 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
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model is Cisco IP Phone 8800 Series
    Check the device label on the phone, or access the phone's web interface at its IP address and look for the model name on the Device Information page, or check via the phone menu under Settings > Device Settings > Model Number
    Affected if The device model is any variant of the Cisco IP Phone 8800 Series (8811, 8841, 8845, 8851, 8851NR, 8861, 8865, etc.)
  2. Identify the firmware version
    Access the phone's web interface and navigate to Device Information > Firmware Version, or on the phone go to Settings > Device Settings > Firmware Version. Compare the displayed version number to the affected range
    Affected if The installed firmware version is exactly 11.0(0.1)
  3. Verify SIP call handling is enabled
    On the phone's web interface, go to Voice > SIP and confirm the SIP Profile is enabled, or check under Settings > Call Control > SIP on the phone display. The vulnerability triggers during SIP call processing
    Affected if SIP is the configured call control protocol (this is the default and typical configuration for these phones)
  4. Check for recent unexplained call drops or phone restarts
    Review any available call logs or system logs if accessible via the web interface under Admin Login > Diagnostics > View Log, or check with your call manager/CUCM administrator for any recorded incidents
    Affected if Active calls are being dropped or the SIP process has restarted unexpectedly while the device runs version 11.0(0.1)

You are affected if you have a Cisco IP Phone 8800 Series device running firmware version 11.0(0.1) with SIP call handling enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Cisco IP Phone 8800 Series devices to fixed release 11.0(0)MP2.153 or 11.0(0)MP2.62 or later to remediate this vulnerability.

Fix this in Ip Phone 8800 Series Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-6656 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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