CVE-2018-6056 in Chrome
Summary
by MITRE
Type confusion could lead to a heap out-of-bounds write in V8 in Google Chrome prior to 64.0.3282.168 allowing a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page.
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Analysis
by VulDB Data Team • 06/23/2023
The vulnerability identified as CVE-2018-6056 represents a critical type confusion issue within the V8 JavaScript engine that powers Google Chrome's browser functionality. This flaw exists in versions prior to 64.0.3282.168 and demonstrates how improper type handling can create severe security implications for web browsers. The vulnerability stems from V8's failure to properly validate type information during JavaScript execution, creating conditions where objects of different types may be incorrectly treated as the same type, leading to unpredictable memory access patterns.
The technical implementation of this vulnerability involves a heap out-of-bounds write condition that occurs when the V8 engine processes certain JavaScript objects with conflicting type information. When a maliciously crafted HTML page attempts to manipulate object types inappropriately, the engine's type confusion allows for memory corruption that can be exploited to execute arbitrary code within the browser's sandboxed environment. This type confusion typically arises during object property access or method invocation where the engine incorrectly assumes an object maintains a specific type structure while it actually contains different data types.
The operational impact of this vulnerability extends beyond simple code execution, as it specifically targets the browser's security sandbox mechanism that isolates web content from the underlying operating system. Attackers can leverage this flaw to bypass security boundaries that normally prevent malicious code from accessing sensitive system resources or executing harmful operations. The remote exploitation capability means that simply visiting a compromised website could trigger the vulnerability, making it particularly dangerous for end users who may not be aware of the malicious nature of the content they are accessing.
From a cybersecurity perspective, this vulnerability aligns with CWE-476 which describes null pointer dereference conditions, though the specific implementation involves type confusion rather than simple pointer issues. The attack vector follows patterns consistent with the ATT&CK framework's technique T1059.007 for JavaScript-based execution and T1070.004 for sandbox evasion techniques. The vulnerability demonstrates how modern browser engines face increasing complexity in managing dynamic typing systems while maintaining security boundaries, particularly when dealing with optimized code paths that assume certain type consistency.
Mitigation strategies for CVE-2018-6056 primarily focus on immediate browser updates to versions 64.0.3282.168 or later where the vulnerability has been patched. Organizations should implement comprehensive patch management processes to ensure all Chrome installations are updated promptly. Additional defensive measures include deploying web application firewalls that can detect and block suspicious JavaScript patterns, implementing content security policies to limit script execution, and conducting regular security assessments of web applications that may be vulnerable to similar type confusion attacks. Network-level protections such as DNS filtering and browser hardening configurations can provide additional layers of defense against exploitation attempts.