CVE-2018-6350 in WhatsApp
Summary
by MITRE
An out-of-bounds read was possible in WhatsApp due to incorrect parsing of RTP extension headers. This issue affects WhatsApp for Android prior to 2.18.276, WhatsApp Business for Android prior to 2.18.99, WhatsApp for iOS prior to 2.18.100.6, WhatsApp Business for iOS prior to 2.18.100.2, and WhatsApp for Windows Phone prior to 2.18.224.
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Analysis
by VulDB Data Team • 09/03/2025
The vulnerability identified as CVE-2018-6350 represents a critical out-of-bounds read flaw within WhatsApp's real-time transport protocol implementation that could potentially enable remote code execution or information disclosure. This issue stems from improper parsing of RTP extension headers, which are essential components in the transmission of multimedia content including voice and video calls within the messaging application. The flaw affects multiple platforms and versions, indicating a widespread impact across WhatsApp's user base and highlighting the critical nature of the vulnerability. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-125, which specifically addresses out-of-bounds read conditions that occur when software attempts to access memory locations beyond the allocated buffer boundaries. The ATT&CK framework categorizes this issue under the technique of privilege escalation through memory corruption vulnerabilities, as attackers could potentially exploit this flaw to gain unauthorized access to system resources.
The technical implementation of this vulnerability occurs during the processing of RTP (Real-time Transport Protocol) packets that contain extension headers used for additional metadata in voice and video communication streams. When WhatsApp's client applications receive these packets, the parsing logic fails to properly validate the length and structure of the extension headers, allowing an attacker to craft malicious packets that cause the application to read memory beyond intended boundaries. This misconfiguration creates a condition where the application's memory management routines are bypassed, potentially exposing sensitive data or allowing for arbitrary code execution within the application's memory space. The vulnerability is particularly dangerous because it operates at the network protocol level, meaning that attackers could exploit it through standard network traffic without requiring physical access to the device or user interaction beyond receiving a call or message.
The operational impact of CVE-2018-6350 extends far beyond individual user privacy concerns, as it represents a potential vector for large-scale surveillance and data harvesting operations. Attackers could leverage this vulnerability to intercept and analyze voice and video call data streams, potentially gaining access to sensitive communications between users. The affected platforms include all major mobile operating systems and desktop environments, making the attack surface extremely broad and the potential for exploitation widespread. Organizations and individuals using WhatsApp for business communications or sensitive personal exchanges would be particularly vulnerable to this type of exploitation. The vulnerability's presence in both standard and business versions of WhatsApp indicates that even enterprise users relying on the platform for confidential communications are at risk, potentially compromising the security of corporate communications and sensitive data transfers.
Mitigation strategies for CVE-2018-6350 require immediate software updates and patches from WhatsApp, as the vulnerability exists within the core application logic rather than being a configuration issue that can be resolved through user settings. Users should immediately update their applications to the patched versions specified in the vulnerability announcement, with the patch releases addressing the buffer overflow conditions in RTP header parsing. Network administrators should implement monitoring for suspicious RTP traffic patterns that could indicate exploitation attempts, while security teams should conduct vulnerability assessments to ensure all instances of the vulnerable software have been updated. The fix implemented by WhatsApp likely involves enhanced input validation and boundary checking within the RTP packet processing routines, ensuring that extension header lengths are properly verified before any memory access operations are performed. Organizations should also consider implementing network segmentation and traffic filtering rules to limit exposure to potential exploitation attempts while awaiting full patch deployment across all affected systems.