CVE-2014-1725 in Chrome
Summary
by MITRE
The base64DecodeInternal function in wtf/text/Base64.cpp in Blink, as used in Google Chrome before 34.0.1847.116, does not properly handle string data composed exclusively of whitespace characters, which allows remote attackers to cause a denial of service (out-of-bounds read) via a window.atob method call.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2014-1725 resides within the Blink rendering engine's base64 decoding implementation in Google Chrome versions prior to 34.0.1847.116. This flaw specifically affects the base64DecodeInternal function located in wtf/text/Base64.cpp, which is responsible for handling base64 encoded data processing. The issue manifests when the function encounters string data that consists entirely of whitespace characters, creating a scenario where normal processing logic fails to properly validate input boundaries. This represents a classic buffer over-read vulnerability that can be exploited through the window.atob JavaScript method, which is commonly used for base64 decoding operations in web applications.
The technical exploitation of this vulnerability occurs through a carefully crafted input string containing only whitespace characters that bypasses normal validation checks within the base64 decoding routine. When the window.atob method processes such input, the base64DecodeInternal function attempts to parse the data without proper boundary checks, leading to an out-of-bounds memory read operation. This type of vulnerability falls under CWE-129, which describes improper handling of buffer boundaries, and specifically aligns with CWE-125, indicating an out-of-bounds read condition. The flaw demonstrates a fundamental weakness in input validation where the function assumes valid data structure without proper sanitization of edge cases involving exclusively whitespace content.
From an operational perspective, this vulnerability creates a significant denial of service risk for affected Chrome users. Remote attackers can craft malicious web pages that trigger the vulnerable code path through the window.atob API, potentially causing browser crashes or system instability. The impact extends beyond simple service disruption as the out-of-bounds read could potentially expose sensitive memory contents or provide a foundation for more sophisticated attacks. The vulnerability affects a broad user base since the window.atob method is commonly used in web applications for data encoding and decoding operations, making it a prime target for exploitation. This type of vulnerability also aligns with ATT&CK technique T1059.007, which covers script-based execution through JavaScript APIs, and T1499.004, representing network denial of service through application layer attacks.
The mitigation strategy for CVE-2014-1725 involves updating to Google Chrome version 34.0.1847.116 or later, which includes the patched base64 decoding implementation. Security researchers and system administrators should prioritize this update as it addresses the core buffer handling issue in the Blink engine's text processing components. Additionally, organizations should implement proper input validation practices in their own applications that utilize base64 decoding functions, ensuring that all inputs are properly sanitized before processing. The fix implemented by Google likely includes enhanced boundary checking and input validation within the base64DecodeInternal function to prevent processing of malformed or edge-case inputs containing only whitespace characters. This vulnerability underscores the importance of robust input validation and memory safety practices in web browser implementations, particularly for core utility functions that handle data transformation operations.