CVE-2016-5142 in Chrome
Summary
by MITRE
The Web Cryptography API (aka WebCrypto) implementation in Blink, as used in Google Chrome before 52.0.2743.116, does not properly copy data buffers, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via crafted JavaScript code, related to NormalizeAlgorithm.cpp and SubtleCrypto.cpp.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability identified as CVE-2016-5142 resides within the Web Cryptography API implementation in Blink, the rendering engine powering Google Chrome and other web browsers. This flaw manifests in the improper handling of data buffer copying mechanisms, creating a critical security gap that affects versions of Chrome prior to 52.0.2743.116. The vulnerability specifically impacts the NormalizeAlgorithm.cpp and SubtleCrypto.cpp components, which are integral to the cryptographic operations performed through the WebCrypto API. The WebCrypto API enables web applications to perform cryptographic operations directly within the browser, making it a crucial component for secure web communications and digital signatures.
The technical exploitation of this vulnerability occurs through crafted JavaScript code that manipulates the buffer copying behavior within the WebCrypto implementation. When malicious code attempts to perform cryptographic operations using the API, the improper buffer handling causes memory management issues that can result in use-after-free conditions. This memory corruption vulnerability arises from the failure to properly validate and copy data buffers during cryptographic algorithm normalization and execution processes. The flaw essentially allows attackers to manipulate memory pointers and access freed memory locations, potentially leading to arbitrary code execution or complete browser crash scenarios.
The operational impact of CVE-2016-5142 extends beyond simple denial of service attacks, as the vulnerability could enable more sophisticated exploitation techniques. Attackers could leverage the use-after-free condition to execute malicious code within the browser context, potentially leading to complete system compromise. The vulnerability affects the core cryptographic operations that websites rely upon for secure communications, making it particularly dangerous for applications handling sensitive data such as financial transactions, personal identification, or confidential business information. Organizations using affected Chrome versions face significant risk of data breaches and unauthorized access to their web applications.
Security researchers have classified this vulnerability under CWE-416, which describes the use of freed memory condition, and it aligns with ATT&CK technique T1059.007 for JavaScript execution. The vulnerability demonstrates how seemingly minor memory management flaws in browser implementations can create substantial security risks. Organizations should immediately update to Chrome version 52.0.2743.116 or later to mitigate this vulnerability, as the fix addresses the buffer copying mechanisms in both NormalizeAlgorithm.cpp and SubtleCrypto.cpp. Additionally, administrators should monitor for any signs of exploitation attempts and consider implementing additional browser security controls such as content security policies and sandboxing measures to reduce the attack surface. The vulnerability highlights the critical importance of proper memory management in web browser implementations and the potential consequences of inadequate buffer handling in cryptographic libraries.