CVE-2024-20533Network attack vector

Stored XSS via improper web UI validation

Published Nov 6, 2024 · Updated Nov 6, 2024

Stored XSS in Cisco IP Phones with Multiplatform Firmware allows remote authenticated users to execute scripts through the web UI. The web UI stores code supplied to specific interface pages without properly validating it, then serves that code in another user's browser context. Exploitation requires enabled Web Access, device Admin credentials, and a user who opens the affected interface, exposing browser-based information to the script.

CVSS severity4.8
Medium
EPSS probability0.28%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Cisco IP Phones with Multiplatform Firmware allows remote authenticated users to execute scripts through the web UI. The web UI stores code supplied to specific interface pages without properly validating it, then serves that code in another user's browser context. Exploitation requires enabled Web Access, device Admin credentials, and a user who opens the affected interface, exposing browser-based information to the script.

The record

CVE
CVE-2024-20533
Published
Nov 6, 2024
Updated
Nov 6, 2024
Vendor
ClamAV
Product
Cisco Session Initiation Protocol (SIP) Software
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Nov 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.0(1)
  2. Affected versionversion=3.1(1)
  3. Affected versionversion=3.1(1)SR1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · Cisco Session Initiation Protocol (SIP) Softwareversion=3.0(1); version=3.1(1); version=3.1(1)SR1
ClamAV · Cisco IP Phones with Multiplatform Firmwareversion=11.0.0; version=11.0.1; version=11.0.1 MSR1-1; version=11.0.2; version=11.1.1; version=11.1.1 MSR1-1; version=11.1.1 MSR2-1; version=11.1.2; version=11.1.2 MSR1-1; version=11.1.2 MSR3-1; version=11.2.1; version=11.2.2; version=11.2.3; version=11.2.3 MSR1-1; version=11.2.4; version=11.3.1; version=11-3-1MPPSR4UPG; version=11.3.1 MSR1-3; version=11.3.1 MSR2-6; version=11-3-1MSR2UPG; version=11.3.1 MSR3-3; version=11.3.1 MSR4-1; version=11.3.2; version=11.3.3; version=11.3.3 MSR1; version=11.3.3 MSR2; version=11.3.4; version=11.3.5; version=11.3.6; version=11.3.6SR1; version=11.3.7; version=11.3.7SR1; version=11.3.7SR2; version=12.0.1; version=12.0.2; version=12.0.3; version=12.0.3SR1; version=12.0.3SR2; version=12.0.4; version=12.0.4SR1; version=12.0.5; version=12.0.5SR1

Published CVSS scores

4.8Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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