dbcve.org
Unified Ip Phone FirmwareOperating system · Cisco

CVE-2018-0332

HIGH · 7.5 CVSS v3.0 Published 2018-06-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 the Session Initiation Protocol (SIP) ingress packet processing of Cisco Unified IP Phone software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a lack of flow-control mechanisms in the software. An attacker could exploit this vulnerability by sending high volumes of SIP INVITE traffic to the targeted device. Successful exploitation could allow the attacker to cause a disruption of services on the targeted IP phone. Cisco Bug IDs: CSCve10064, CSCve14617, CSCve14638, CSCve14683, CSCve20812, CSCve20926, CSCve20945.

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

This vulnerability exists in the SIP (Session Initiation Protocol) ingress packet processing component of Cisco Unified IP Phone software. The root cause is a lack of flow-control mechanisms, allowing an unauthenticated remote attacker to send high volumes of SIP INVITE traffic to exhaust resources and cause a denial of service on the targeted IP phone.

MitigationApply the Cisco-provided software update/patch for Cisco Unified IP Phone firmware to address the flow-control deficiency in SIP processing. Consider implementing network-level rate limiting or SIP traffic filtering on upstream devices as a compensating control until the patch can be deployed.

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
Unified Ip Phone FirmwareOperating system
Affected:= 9.9\(9.99002.1\)
Ip Phone FirmwareOperating system
Affected:= 9.4\(2\)sr3.1= 9.4\(2\)sr4

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
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/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. Identify the Cisco IP Phone firmware version
    Access the phone's web interface or use the phone's settings menu to view the firmware version. On the web interface, go to Info > Device Information and look for the Firmware Version field. Alternatively, press the Settings button on the phone and navigate to Model Information.
    Affected if The displayed firmware version matches 9.9(9.99002.1), 9.4(2)sr3.1, or 9.4(2)sr4 exactly.
  2. Confirm SIP protocol is enabled
    Access the phone's web interface and navigate to SIP Settings or Proxy. Verify that the SIP Proxy is configured and the phone is registered to a SIP proxy/registrar. Check if the SIP Transport is set to UDP or TCP.
    Affected if SIP is enabled and the phone is configured to accept SIP registrations.
  3. Check SIP INVITE processing exposure
    Examine the phone's SIP configuration for settings related to incoming calls or anonymous calls. Look for options such as 'Accept Anonymous Calls' or 'Block External Calls' in the SIP settings menu.
    Affected if The phone accepts unauthenticated or anonymous SIP INVITE requests (Accept Anonymous Calls is enabled).
  4. Review network exposure of SIP port
    Check if UDP/TCP port 5060 (standard SIP port) is open to untrusted networks. Verify if the phone's IP address is directly accessible from the internet or an untrusted VLAN segment.
    Affected if The SIP port is accessible from untrusted network segments or the internet without firewall protection.
  5. Look for signs of resource exhaustion
    Check the phone's status indicators for unusual behavior such as slow response, repeated reboots, or inability to register. In the web interface, monitor call history or event logs for high volumes of incoming INVITE attempts.
    Affected if The phone exhibits denial of service symptoms or logs show excessive incoming SIP INVITE traffic.

A user is affected if their Cisco IP Phone runs firmware version 9.9(9.99002.1), 9.4(2)sr3.1, or 9.4(2)sr4 AND has SIP enabled with exposure to unauthenticated SIP INVITE traffic.

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

Apply the Cisco-provided software update/patch for Cisco Unified IP Phone firmware to address the flow-control deficiency in SIP processing. Consider implementing network-level rate limiting or SIP traffic filtering on upstream devices as a compensating control until the patch can be deployed.

Fix this in Unified Ip Phone Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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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-2018-0332 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