CVE-2016-1691 in Chrome
Summary
by MITRE
Skia, as used in Google Chrome before 51.0.2704.63, mishandles coincidence runs, which allows remote attackers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via crafted curves, related to SkOpCoincidence.cpp and SkPathOpsCommon.cpp.
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-1691 resides within Skia, a 2D graphics library that serves as a core component of Google Chrome browser before version 51.0.2704.63. This flaw manifests in the handling of coincidence runs during path operations, specifically affecting the SkOpCoincidence.cpp and SkPathOpsCommon.cpp source files. The issue represents a critical security concern that demonstrates how mathematical operations involving geometric paths can introduce exploitable conditions within graphics rendering pipelines.
The technical implementation of this vulnerability stems from improper management of coincidence detection algorithms within Skia's path operations. When processing crafted curves that create coincident segments, the library fails to properly validate or handle edge cases during the coincidence run processing phase. This mismanagement leads to heap-based buffer overflow conditions where memory allocation calculations become invalid due to miscalculated array bounds or improper memory access patterns. The flaw essentially allows attackers to manipulate the graphics rendering engine through carefully constructed path data that triggers unexpected behavior in the coincidence detection subsystem.
From an operational perspective, this vulnerability enables remote attackers to execute denial of service attacks against affected Chrome browsers by simply presenting maliciously crafted vector graphics or web content that utilizes specific curve configurations. The impact extends beyond simple service disruption as the buffer overflow conditions could potentially lead to arbitrary code execution depending on memory layout and exploitation circumstances. The vulnerability affects web applications that utilize complex vector graphics, SVG content, or any rendering that leverages Skia's path operations, making it particularly dangerous in environments where users encounter untrusted content.
The root cause of this vulnerability aligns with CWE-121, heap-based buffer overflow, and demonstrates characteristics consistent with CWE-787, out-of-bounds write, as the flaw involves writing data beyond allocated memory boundaries. From an ATT&CK framework perspective, this vulnerability maps to technique T1203, Exploitation for Client Execution, and T1059, Command and Scripting Interpreter, as it enables remote code execution through crafted web content. The vulnerability also relates to T1489, Service Stop, through the denial of service component, and represents a critical entry point for attackers seeking to compromise browser environments.
Mitigation strategies for CVE-2016-1691 primarily involve immediate patching of affected Chrome browser versions to 51.0.2704.63 or later, which includes fixes for the coincidence run handling logic. Organizations should also implement network-level protections such as web application firewalls that can detect and block suspicious vector graphics content, along with browser hardening measures that restrict access to potentially malicious web content. Additionally, regular security updates and vulnerability assessments should be conducted to ensure all components utilizing Skia graphics libraries remain protected against similar path operation vulnerabilities. The fix implemented by Google addressed the specific edge cases in coincidence detection algorithms and introduced proper bounds checking to prevent heap memory corruption during path operation processing.