CVE-2016-1677 in Chrome
Summary
by MITRE
uri.js in Google V8 before 5.1.281.26, as used in Google Chrome before 51.0.2704.63, uses an incorrect array type, which allows remote attackers to obtain sensitive information by calling the decodeURI function and leveraging "type confusion."
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-1677 resides within the Google V8 JavaScript engine's uri.js implementation, specifically affecting versions prior to 5.1.281.26. This flaw manifests in Google Chrome versions before 51.0.2704.63, creating a critical security risk that stems from improper array type handling during URI decoding operations. The issue represents a type confusion vulnerability that can be exploited remotely to extract sensitive information from affected systems.
The technical root cause of this vulnerability lies in the incorrect array type handling within the decodeURI function implementation. When processing URI-encoded strings, the V8 engine fails to properly validate or maintain consistent array types during the decoding process, leading to a scenario where different data types can be incorrectly interpreted as the same type. This type confusion creates opportunities for attackers to manipulate memory layouts and access unintended data segments that should remain protected. The flaw specifically impacts how the engine manages internal array representations during URI parsing operations, allowing for potential information disclosure through carefully crafted malicious inputs.
From an operational standpoint, this vulnerability enables remote attackers to perform information disclosure attacks without requiring any local privileges or user interaction. An attacker can craft malicious URI strings that, when processed through the vulnerable decodeURI function, can cause the engine to leak sensitive memory contents including stack data, heap information, or other confidential data that should not be accessible through normal JavaScript execution. The impact extends beyond simple data leakage as this vulnerability can potentially be leveraged in more sophisticated attacks, including privilege escalation or further exploitation of other vulnerabilities present in the browser environment.
The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and more specifically relates to type confusion issues that can lead to information disclosure. From an ATT&CK framework perspective, this vulnerability maps to techniques involving information gathering and privilege escalation, as it allows adversaries to extract sensitive information that could be used to further compromise systems. The attack surface is particularly concerning given that URI decoding is a common operation in web applications and the vulnerability can be triggered through standard web browsing activities without requiring any special user actions beyond visiting a malicious website.
Mitigation strategies for CVE-2016-1677 primarily involve updating to patched versions of Google Chrome and the underlying V8 engine. Organizations should immediately deploy Chrome version 51.0.2704.63 or later, which contains the necessary fixes to address the type confusion issue in uri.js. Additionally, administrators should consider implementing web application firewalls and content filtering solutions that can detect and block suspicious URI patterns. Regular patch management procedures should be enforced to ensure all browser components remain up to date with the latest security fixes. Network monitoring should also be enhanced to detect unusual URI decoding patterns that might indicate exploitation attempts, and security teams should maintain awareness of related vulnerabilities that could compound the risks associated with this particular flaw.