CVE-2016-1702 in Chrome
Summary
by MITRE
The SkRegion::readFromMemory function in core/SkRegion.cpp in Skia, as used in Google Chrome before 51.0.2704.79, does not validate the interval count, which allows remote attackers to cause a denial of service (out-of-bounds read) via crafted serialized data.
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Analysis
by VulDB Data Team • 08/23/2022
The vulnerability identified as CVE-2016-1702 resides within the Skia graphics library component that serves as a core rendering engine for Google Chrome and numerous other applications. This flaw manifests in the SkRegion::readFromMemory function located in the core/SkRegion.cpp file, where the implementation fails to properly validate the interval count parameter during deserialization of serialized data. The absence of validation creates a critical security gap that enables malicious actors to manipulate the interval count field in crafted serialized data streams. When Chrome processes such malformed data, the function attempts to read memory locations beyond the allocated buffer boundaries, resulting in an out-of-bounds read condition that can be exploited for denial of service attacks.
The technical exploitation of this vulnerability follows a well-defined pattern where attackers construct specially crafted serialized data containing an invalid interval count that exceeds the expected bounds of the memory buffer. This improper validation allows the readFromMemory function to traverse memory locations that were not intended to be accessed, potentially leading to information disclosure or system instability. The vulnerability specifically affects Google Chrome versions prior to 51.0.2704.79, making it a significant concern for users running outdated browser versions. From a cybersecurity perspective, this issue represents a classic buffer over-read vulnerability that can be classified under CWE-129 as an insufficient input validation problem, where the system fails to properly validate the range or value of input data before processing it.
The operational impact of CVE-2016-1702 extends beyond simple denial of service scenarios, as the out-of-bounds read condition can potentially expose sensitive memory contents to attackers. When exploited in remote attack scenarios, this vulnerability allows adversaries to craft malicious web content that, when rendered by an affected browser, triggers the vulnerable code path. The attack surface is particularly broad since Skia is widely used across multiple platforms and applications, making this vulnerability potentially exploitable in various contexts including web browsing, document rendering, and image processing applications. The vulnerability aligns with ATT&CK technique T1059.007 for remote code execution through web-based attacks, though the current exploitation primarily targets denial of service rather than arbitrary code execution.
Mitigation strategies for this vulnerability primarily focus on immediate remediation through browser updates to versions that contain the patched Skia implementation. Organizations should prioritize updating their Chrome installations to version 51.0.2704.79 or later, which includes the necessary validation checks for interval counts in serialized data. Additionally, system administrators can implement network-level protections such as web application firewalls that monitor for suspicious serialized data patterns and can block known malicious payloads. The fix implemented by Google addresses the root cause by introducing proper validation of interval count values before processing serialized data, ensuring that the readFromMemory function operates within safe memory boundaries. Security monitoring should include detection of unusual memory access patterns and out-of-bounds read attempts that may indicate exploitation attempts, particularly in environments where users may encounter untrusted web content.