CVE-2025-62482

Executive Summary

CVE-2025-62482 is a Cross-Site Scripting (XSS) vulnerability in Zoom Workplace for Windows prior to version 6.5.10. An unauthenticated attacker can exploit this flaw via network access to impact the integrity of the application. The vulnerability has a CVSS score of 4.3 (Medium) and an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or exploit code has been released. The vendor, Zoom, has not yet confirmed a patch status.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a client-side XSS in a proprietary Windows application (Zoom Workplace). No supply chain implications are identified.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must click a crafted link or interact with malicious content.
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: Low (I:L)
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability requires user interaction and only impacts integrity (e.g., content injection, defacement). No data theft or service disruption.

Deep Dive & Mechanics

The vulnerability resides in the Zoom Workplace for Windows client. An unauthenticated attacker can inject malicious JavaScript into a vulnerable component (likely a chat message, meeting invitation, or shared content) that is rendered without proper sanitization. When a victim interacts with the crafted content (e.g., clicks a link or views a message), the script executes in the context of the Zoom application, allowing the attacker to modify displayed content, steal session tokens, or perform actions on behalf of the user.

Root Cause: Insufficient input validation and output encoding in the Zoom Workplace client’s rendering engine. The application fails to escape HTML/JavaScript special characters before displaying user-controlled data.

Attack Vector: Network-based. The attacker sends a crafted message or link via Zoom’s chat, meeting, or email integration. No authentication is required to send the payload.

Impact: Integrity compromise – the attacker can alter the appearance of the Zoom interface, inject fake notifications, or redirect users to malicious sites. No direct data exfiltration or privilege escalation.

Vulnerable vs. Patched Code

No specific code snippets are available. However, the fix likely involves:

• Vulnerable: The application directly inserts user input into the DOM without sanitization.

  // Vulnerable example (conceptual)
  document.getElementById('message').innerHTML = userInput;
  

• Patched: The application uses safe methods like textContent or a sanitization library.

  // Patched example (conceptual)
  document.getElementById('message').textContent = userInput;
  // Or using DOMPurify
  document.getElementById('message').innerHTML = DOMPurify.sanitize(userInput);
  

Exploitation & Lab Setup

Red Team

Prerequisites:

• Zoom Workplace for Windows version < 6.5.10
• Network access to the target (e.g., via Zoom chat or meeting)
• A crafted XSS payload

Steps:

1. Craft a malicious JavaScript payload (e.g., <script>alert('XSS')</script> or a more sophisticated payload to steal session cookies).
2. Send the payload via Zoom chat, meeting invitation, or shared content.
3. Wait for the victim to interact with the payload (e.g., click a link or view the message).
4. The script executes in the victim’s Zoom client, allowing integrity manipulation.

Example Payload:

<img src=x onerror="alert('XSS')">

Note: No public exploit code is available. This is a conceptual demonstration.

Blue Team

Detection:

• Monitor Zoom client logs for unusual JavaScript execution or DOM modifications.
• Use endpoint detection and response (EDR) tools to detect script injection attempts.
• Deploy web application firewalls (WAF) to filter malicious payloads in Zoom traffic.

Hunting:

• Search for Zoom client processes spawning unexpected child processes (e.g., cmd.exe, powershell.exe).
• Look for network connections to known malicious domains from the Zoom client.

Mitigation:

• Update Zoom Workplace to version 6.5.10 or later.
• Disable JavaScript in Zoom client settings if possible.
• Educate users not to click on suspicious links or messages.

Indicators of Compromise (IOCs)

• Network:

  • Outbound connections to attacker-controlled domains from the Zoom client.
  • Unusual HTTP requests containing XSS payloads (e.g., <script>, onerror, alert).

• Host:

  • Zoom client logs showing unexpected JavaScript execution.
  • Modified DOM elements in Zoom’s interface (e.g., fake notifications, altered text).
  • Presence of temporary files containing injected scripts.

• File:

  • No specific file IOCs identified.

Detection Engineering

YARA Rule

rule CVE_2025_62482_XSS_Zoom {
    meta:
        description = "Detects XSS payloads targeting Zoom Workplace for Windows"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2025-62482"
    strings:
        $xss1 = "<script>" nocase
        $xss2 = "onerror=" nocase
        $xss3 = "onload=" nocase
        $xss4 = "javascript:" nocase
        $xss5 = "alert(" nocase
    condition:
        any of ($xss*) and filesize < 10KB
}

Sigma Rule

title: Zoom Workplace XSS Payload Detection
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects XSS payloads in Zoom Workplace network traffic
author: Valters IT
date: 2025-01-01
logsource:
    category: network
    product: suricata
detection:
    selection:
        http.uri|contains:
            - '<script>'
            - 'onerror='
            - 'onload='
            - 'javascript:'
            - 'alert('
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in Zoom features
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62482 Zoom Workplace XSS Payload"; flow:to_server,established; content:"<script>"; nocase; sid:1000001; rev:1;)
alert http any any -> any any (msg:"CVE-2025-62482 Zoom Workplace XSS Payload"; flow:to_server,established; content:"onerror="; nocase; sid:1000002; rev:1;)
alert http any any -> any any (msg:"CVE-2025-62482 Zoom Workplace XSS Payload"; flow:to_server,established; content:"onload="; nocase; sid:1000003; rev:1;)
alert http any any -> any any (msg:"CVE-2025-62482 Zoom Workplace XSS Payload"; flow:to_server,established; content:"javascript:"; nocase; sid:1000004; rev:1;)
alert http any any -> any any (msg:"CVE-2025-62482 Zoom Workplace XSS Payload"; flow:to_server,established; content:"alert("; nocase; sid:1000005; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Update Zoom Workplace for Windows to version 6.5.10 or later.
2. If patching is not possible, restrict network access to Zoom services and disable chat/meeting features.
3. Implement Content Security Policy (CSP) headers in Zoom’s web components if applicable.

Long-Term Measures:

• Enforce strict input validation and output encoding in all Zoom client components.
• Conduct regular security audits and penetration testing.
• Monitor for new advisories from Zoom regarding this CVE.

Workarounds:

• Disable JavaScript in Zoom client settings (if available).
• Use a web proxy to filter malicious payloads.
• Educate users to avoid clicking on suspicious links or messages.

Valters IT
Securing Digital Frontiers