dbcve.org
Spa514g FirmwareOperating system · Cisco

CVE-2018-0389

HIGH · 7.5 CVSS v3.0 Published 2019-03-13
Fix available
A fix is available. Upgrade to after 7.6.2sr2 or later.
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 implementation of Session Initiation Protocol (SIP) processing in Cisco Small Business SPA514G IP Phones could allow an unauthenticated, remote attacker to cause an affected device to become unresponsive, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of SIP request messages by an affected device. An attacker could exploit this vulnerability by sending crafted SIP messages to an affected device. A successful exploit could allow the attacker to cause the affected device to become unresponsive, resulting in a DoS condition that persists until the device is restarted manually. Cisco has not released software updates that address this vulnerability. This vulnerability affects Cisco Small Business SPA514G IP Phones that are running firmware release 7.6.2SR2 or earlier.

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

The vulnerability exists in SIP processing on Cisco Small Business SPA514G IP Phones running firmware 7.6.2SR2 or earlier. An unauthenticated remote attacker can send crafted SIP request messages to cause the device to become unresponsive, requiring manual restart to recover.

MitigationSince Cisco has not released patches, implement network-based compensating controls such as SIP-aware firewall rules or VLAN segmentation to restrict SIP traffic to trusted sources, and consider replacing affected devices with supported models.

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
Spa514g FirmwareOperating system
Affected:<= 7.6.2sr2

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. Check the firmware version of the Cisco SPA514G IP Phone
    Access the phone's web interface and navigate to Admin Login > Advanced > Info > Firmware Version to retrieve the current firmware version string
    Affected if The firmware version is 7.6.2SR2 or any earlier version such as 7.6.1, 7.5.x, or older releases
  2. Verify if SIP protocol processing is enabled on the device
    Navigate to the phone's web interface: Admin Login > Advanced > SIP > SIP Settings, or check Line 1/Line 2 settings for SIP proxy configuration
    Affected if SIP is enabled and the device has SIP proxy or server settings configured, since the vulnerability exists specifically in SIP processing
  3. Determine if the SIP port is accessible from untrusted networks
    Scan the device from an external or untrusted network segment on UDP/TCP port 5060 (or the configured SIP port), or review firewall rules protecting the device
    Affected if The device's SIP port (default 5060) is reachable from untrusted or internet-facing networks without proper filtering or access controls

Your environment is affected if you have Cisco SPA514G phones running firmware 7.6.2SR2 or earlier with SIP enabled and the SIP port exposed to untrusted networks.

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
Upgrade available Upgrade to a release after 7.6.2sr2
Interim mitigation

Since Cisco has not released patches, implement network-based compensating controls such as SIP-aware firewall rules or VLAN segmentation to restrict SIP traffic to trusted sources, and consider replacing affected devices with supported models.

Fix this in Spa514g Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2018-0389 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