CVE-2020-1886 in WhatsApp
Summary
by MITRE
A buffer overflow in WhatsApp for Android prior to v2.20.11 and WhatsApp Business for Android prior to v2.20.2 could have allowed an out-of-bounds write via a specially crafted video stream after receiving and answering a malicious video call.
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Analysis
by VulDB Data Team • 11/12/2020
This vulnerability represents a critical buffer overflow flaw in the multimedia processing components of WhatsApp for Android applications. The issue stems from inadequate input validation and memory management within the video call handling mechanism, specifically when processing specially crafted video streams. The vulnerability affects both standard WhatsApp and WhatsApp Business applications across Android platforms, with versions prior to 2.20.11 and 2.20.2 respectively. The flaw manifests during the execution of malicious video calls where the application fails to properly bounds-check memory allocations when processing incoming video streams, creating opportunities for arbitrary memory writes beyond allocated buffers.
The technical exploitation of this vulnerability occurs through a carefully constructed video call that contains malformed video stream data. When a victim receives and answers such a malicious call, the application's video processing pipeline attempts to decode and render the video content without proper boundary checks. This allows an attacker to overwrite adjacent memory locations, potentially leading to arbitrary code execution or application crash. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. The attack vector specifically maps to the ATT&CK technique T1203, where adversaries leverage application vulnerabilities to execute malicious code through targeted exploitation of memory corruption flaws.
From an operational perspective, this vulnerability presents significant risk to end users as it requires minimal user interaction beyond accepting a malicious video call. The attack can be executed remotely without requiring physical access or complex prerequisites, making it particularly dangerous in enterprise environments where mobile device security is paramount. The exploitation chain involves social engineering to诱导 users to accept video calls, followed by automatic trigger of the buffer overflow during media processing. This vulnerability impacts the integrity and availability of the messaging application, potentially allowing attackers to gain persistent access to device resources or escalate privileges within the application context.
The recommended mitigations include immediate application updates to versions 2.20.11 or later for WhatsApp and 2.20.2 or later for WhatsApp Business. Organizations should implement mobile device management policies that enforce automatic application updates and monitor for suspicious video call patterns. Network-level defenses should include traffic inspection for unusual video stream characteristics, while endpoint protection solutions should be configured to detect and block malicious media processing activities. Additionally, user awareness training should emphasize the risks of accepting video calls from unknown or untrusted sources, as the vulnerability can be exploited through social engineering tactics that leverage human factors to achieve successful exploitation.