CVE-2025-27439: Zoom Meeting SDK Privilege Escalation

CVE-2025-27439 Overview

CVE-2025-27439 is a buffer underflow vulnerability affecting multiple Zoom Workplace applications across various platforms. This memory corruption flaw allows an authenticated user to conduct privilege escalation via network access, potentially compromising the integrity and confidentiality of affected systems.

Buffer underflow vulnerabilities (CWE-124) occur when a program attempts to access memory before the beginning of an allocated buffer, leading to unpredictable behavior including memory corruption, application crashes, or arbitrary code execution. In this case, the vulnerability affects Zoom's core communication infrastructure used by millions of enterprise users worldwide.

Critical Impact

An authenticated attacker can exploit this buffer underflow vulnerability to escalate privileges on affected systems through network access, potentially gaining elevated access to sensitive meeting data and system resources.

Affected Products

• Zoom Meeting Software Development Kit (Android, iOS, Linux, macOS, Windows)
• Zoom Rooms (Android, iPadOS, macOS, Windows)
• Zoom Rooms Controller (Android, Linux, macOS, Windows)
• Zoom Workplace (Android, iOS)
• Zoom Workplace Desktop (Linux, macOS, Windows)
• Zoom Workplace Virtual Desktop Infrastructure (Windows)

Discovery Timeline

• 2025-03-11 - CVE-2025-27439 published to NVD
• 2025-10-22 - Last updated in NVD database

Technical Details for CVE-2025-27439

Vulnerability Analysis

This buffer underflow vulnerability represents a serious memory safety issue in Zoom's codebase. Buffer underflows occur when software reads or writes data before the start of an allocated memory buffer, typically caused by incorrect pointer arithmetic or improper bounds checking during memory operations.

The vulnerability is exploitable over the network by an authenticated user, meaning an attacker needs valid credentials to access a Zoom environment but requires no special privileges to launch the attack. Once exploited, the attacker can achieve privilege escalation, potentially gaining administrative or system-level access that exceeds their original authorization level.

The attack complexity is considered low, with no user interaction required beyond the initial authentication. This makes the vulnerability particularly dangerous in enterprise environments where Zoom applications are widely deployed and many users have legitimate authenticated access.

Root Cause

The root cause of CVE-2025-27439 is a buffer underflow condition (CWE-124) within the affected Zoom applications. This typically occurs when:

• Pointer arithmetic calculations result in addresses before the buffer's starting boundary
• Array index calculations produce negative values that are not properly validated
• Improper handling of buffer offsets during data processing operations

The vulnerability spans multiple Zoom products across different operating systems, suggesting the flaw exists in shared code libraries or core components used across the Zoom Workplace product family.

Attack Vector

The attack vector for this vulnerability is network-based, requiring authenticated access to the target Zoom environment. An attacker can exploit this vulnerability by:

1. Authenticating to a vulnerable Zoom application using valid credentials
2. Sending specially crafted network requests designed to trigger the buffer underflow condition
3. Manipulating memory operations to achieve privilege escalation
4. Gaining elevated access to system resources or sensitive data

The vulnerability affects the confidentiality, integrity, and availability of affected systems. Successful exploitation could allow attackers to access sensitive meeting content, modify system configurations, or disrupt Zoom services entirely.

For detailed technical information about this vulnerability, refer to the Zoom Security Bulletin ZSB-25011.

Detection Methods for CVE-2025-27439

Indicators of Compromise

• Unexpected crashes or memory access violations in Zoom application processes
• Anomalous privilege escalation events associated with Zoom user accounts
• Unusual network traffic patterns to/from Zoom application processes
• System logs indicating memory corruption or buffer-related errors in Zoom components

Detection Strategies

• Monitor Zoom application logs for signs of memory corruption or abnormal termination
• Implement network traffic analysis to detect malformed packets targeting Zoom services
• Deploy endpoint detection solutions capable of identifying exploitation attempts against memory vulnerabilities
• Audit user privilege changes and escalation events related to Zoom application contexts

Monitoring Recommendations

• Enable verbose logging on Zoom Rooms and Workplace applications to capture potential exploitation attempts
• Configure SIEM rules to alert on unusual authentication patterns followed by privilege escalation
• Monitor system crash reports for patterns indicative of buffer underflow exploitation
• Track version information across deployed Zoom applications to ensure timely patching

How to Mitigate CVE-2025-27439

Immediate Actions Required

• Update all affected Zoom applications to the latest patched versions immediately
• Review network access controls to limit exposure of Zoom services to untrusted networks
• Audit user accounts with access to Zoom infrastructure and remove unnecessary privileges
• Enable enhanced logging on all Zoom deployments to detect potential exploitation attempts

Patch Information

Zoom has released security patches addressing this vulnerability as documented in Security Bulletin ZSB-25011. Organizations should prioritize updating the following products:

• Zoom Meeting Software Development Kit on all platforms
• Zoom Rooms for Android, iPadOS, macOS, and Windows
• Zoom Rooms Controller for all supported operating systems
• Zoom Workplace and Workplace Desktop applications
• Zoom Workplace Virtual Desktop Infrastructure

Administrators should verify patch status across all Zoom deployments and establish automated update mechanisms where possible.

Workarounds

• Implement network segmentation to restrict access to Zoom services from untrusted network segments
• Apply application allowlisting to prevent unauthorized code execution in Zoom application contexts
• Enable multi-factor authentication for all Zoom accounts to add an additional authentication layer
• Consider temporarily restricting Zoom functionality to essential features until patches can be applied

# Verify Zoom application version on Windows
# Navigate to Zoom installation directory and check version
dir "C:\Program Files\Zoom\bin\Zoom.exe" | findstr /i "version"

# For Linux systems, check installed package version
dpkg -l | grep -i zoom
# or for RPM-based systems
rpm -qa | grep -i zoom