CVE-2015-6773 in Chrome
Summary
by MITRE
The convolution implementation in Skia, as used in Google Chrome before 47.0.2526.73, does not properly constrain row lengths, which allows remote attackers to cause a denial of service (out-of-bounds memory access) or possibly have unspecified other impact via crafted graphics data.
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Analysis
by VulDB Data Team • 06/28/2022
The vulnerability identified as CVE-2015-6773 resides within the Skia graphics library implementation that powers Google Chrome's rendering capabilities prior to version 47.0.2526.73. This flaw manifests in the convolution operation handling where the system fails to properly validate and constrain row lengths during graphics processing. The issue represents a classic buffer overread condition that can be exploited through maliciously crafted graphics content delivered via web pages or embedded media. Skia's convolution implementation is responsible for processing various graphical operations including image filtering, blur effects, and other visual transformations that are commonly used in modern web applications. When the system processes malformed convolution parameters without adequate bounds checking, it can lead to memory access violations that compromise system stability and potentially provide attack vectors for more sophisticated exploits.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array index values, and CWE-787, which covers out-of-bounds write operations. The flaw specifically enables attackers to manipulate convolution parameters in ways that exceed allocated memory boundaries, creating opportunities for denial of service conditions where the browser process crashes or becomes unresponsive. The vulnerability can be leveraged through the ATT&CK technique T1203, where adversaries exploit software vulnerabilities to gain system access or cause service disruption. In the context of browser security, this represents a critical path for remote code execution or persistent denial of service attacks, as the convolution operations are frequently used in web content rendering, particularly in complex web applications, multimedia presentations, and rich internet applications that rely heavily on visual effects.
The operational impact of CVE-2015-6773 extends beyond simple browser crashes, as it can be weaponized to create persistent service disruptions for users accessing compromised web content. Attackers can craft malicious SVG or HTML5 canvas elements that trigger the vulnerable convolution code path, potentially causing browsers to consume excessive memory resources or access invalid memory locations. This vulnerability particularly affects users of older Chrome versions who have not received security updates, creating a significant risk in enterprise environments where legacy browser versions may still be in use. The exploitability of this flaw increases when combined with other browser vulnerabilities, as demonstrated in various exploit frameworks that have historically targeted similar memory corruption issues in graphics libraries. Organizations must consider this vulnerability as part of broader security hygiene practices, particularly when dealing with untrusted web content and ensuring proper patch management across all browser installations.
Mitigation strategies for CVE-2015-6773 primarily focus on immediate remediation through software updates, as Google released version 47.0.2526.73 to address the specific bounds checking deficiencies in Skia's convolution implementation. System administrators should prioritize patching affected Chrome installations to prevent exploitation, while also implementing network-level protections such as content filtering and sandboxing mechanisms to limit potential damage from successful attacks. The vulnerability highlights the importance of proper input validation in graphics processing libraries and underscores the need for comprehensive security testing of rendering engines. Organizations should also consider implementing browser hardening measures, including disabling unnecessary graphics features, restricting access to potentially vulnerable APIs, and monitoring for unusual memory access patterns that might indicate exploitation attempts. Regular security assessments of web applications and browser configurations help identify and remediate similar vulnerabilities before they can be exploited in the wild, particularly given the historical precedent of similar issues in graphics processing libraries that have resulted in significant security incidents.