dbcve.org
Spa 301 FirmwareOperating system · Cisco

CVE-2024-20454

CRITICAL · 9.8 CVSS v3.1 Published 2024-08-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
Multiple vulnerabilities in the web-based management interface of Cisco Small Business SPA300 Series IP Phones and Cisco Small Business SPA500 Series IP Phones could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system with root privileges. These vulnerabilities exist because incoming HTTP packets are not properly checked for errors, which could result in a buffer overflow. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to overflow an internal buffer and execute arbitrary commands at the root privilege level.

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

Buffer overflow vulnerability in the web-based management interface of Cisco Small Business SPA300 and SPA500 Series IP Phones allows remote unauthenticated attackers to execute arbitrary commands with root privileges by sending specially crafted HTTP requests that overflow an internal buffer due to improper error checking on incoming packets.

MitigationApply Cisco-provided firmware updates when available; as a compensating control, restrict or disable web-based management interface access and place affected devices behind a firewall or VPN.

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
Spa 301 FirmwareOperating system
Affected:all versions
Spa 303 FirmwareOperating system
Affected:all versions
Spa 501g FirmwareOperating system
Affected:all versions
Spa 502g FirmwareOperating system
Affected:all versions
Spa 504g FirmwareOperating system
Affected:all versions
Spa 508g FirmwareOperating system
Affected:all versions
Spa 509g FirmwareOperating system
Affected:all versions
Spa 512g FirmwareOperating system
Affected:all versions

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 checks

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

  1. Identify the IP phone model
    Access the device's web interface, check the admin page, or use SNMP/SSH to query the device model. Common paths: http://<device-ip>/admin or check the device label.
    Affected if The model is one of: Spa 301, Spa 303, Spa 501g, Spa 502g, Spa 504g, Spa 508g, Spa 509g, or Spa 512g.
  2. Verify the firmware version
    Log into the device web interface and navigate to the firmware or status page, typically at http://<device-ip>/admin/upgrade or http://<device-ip>/admin/status. The firmware version is displayed on the main status screen.
    Affected if Any firmware version is installed, as all versions of the affected models are vulnerable.
  3. Confirm the web-based management interface is enabled
    Check the device configuration under 'Web Server' or 'Management' settings in the web interface. The web interface is typically enabled by default on port 80 or 443.
    Affected if The web-based management interface is currently enabled and accessible on the network.
  4. Verify network accessibility of the management interface
    Attempt to access http://<device-ip> or https://<device-ip> from a remote location, or use a port scanner to check if ports 80 or 443 are open on the device IP address.
    Affected if The web management interface is reachable from untrusted networks.

You are affected if you have a Cisco Spa 300 or 500 series IP phone model ( Spa 301, 303, 501g, 502g, 504g, 508g, 509g, or 512g) with the web-based management interface enabled and accessible on your network.

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 Cisco-provided firmware updates when available; as a compensating control, restrict or disable web-based management interface access and place affected devices behind a firewall or VPN.

Fix this in Spa 301 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,304.

Scan for this in your stack

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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-2024-20454 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