CVE-2018-6174 in Chrome
Summary
by MITRE
Integer overflows in Swiftshader in Google Chrome prior to 68.0.3440.75 potentially allowed a remote attacker to execute arbitrary code via a crafted HTML page.
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Analysis
by VulDB Data Team • 07/17/2024
The vulnerability identified as CVE-2018-6174 represents a critical integer overflow flaw within Swiftshader, the software rasterizer component of Google Chrome that is used for rendering graphics when hardware acceleration is unavailable or disabled. This vulnerability exists in Chrome versions prior to 68.0.3440.75 and creates a pathway for remote code execution through maliciously crafted HTML pages. The flaw specifically manifests in how Swiftshader handles certain integer calculations during graphic rendering operations, creating conditions where arithmetic overflow can occur and potentially be exploited by attackers.
The technical nature of this vulnerability stems from improper handling of integer arithmetic operations within the Swiftshader library, which is designed to perform graphics computations using software-based rendering rather than relying on GPU hardware. When processing specific graphic elements in HTML pages, the software rasterizer performs calculations that can exceed the maximum representable value for integer data types, leading to wraparound behavior that can be manipulated to overwrite memory locations. This type of vulnerability falls under the CWE-190 category of integer overflow, which is a well-documented weakness that has been exploited in numerous security incidents across different software platforms. The integer overflow occurs during the calculation of buffer sizes or loop counters used in graphic rendering algorithms, where attackers can craft input data that causes these calculations to produce unexpectedly large values.
The operational impact of this vulnerability is severe as it enables remote code execution without requiring user interaction beyond visiting a malicious webpage. Attackers can construct HTML pages containing specially crafted graphics elements that trigger the integer overflow condition in Swiftshader, potentially allowing them to execute arbitrary code with the privileges of the Chrome browser process. This represents a significant threat vector since Chrome is widely used across different operating systems and platforms, making the attack surface extensive. The vulnerability is particularly dangerous because it operates at the graphics rendering layer, which means it can be exploited through standard web browsing activities without requiring specialized attack vectors or user consent. The exploitability factor is enhanced by the fact that Swiftshader is often enabled by default in Chrome, especially on systems where hardware acceleration is not available or has been disabled, increasing the likelihood of successful exploitation.
The mitigation strategies for CVE-2018-6174 primarily involve updating to Chrome version 68.0.3440.75 or later, which includes patches that address the integer overflow conditions in Swiftshader. Organizations should implement comprehensive patch management procedures to ensure timely deployment of security updates across all Chrome installations. Additionally, security measures such as sandboxing, which is already enabled in Chrome, can provide additional protection layers that limit the potential damage from successful exploits. Network security controls including web application firewalls and content filtering systems can also help detect and block malicious HTML content that attempts to trigger this vulnerability. From a defensive perspective, the ATT&CK framework categorizes this vulnerability under the technique of exploitation for code execution, specifically targeting the software rendering components of browsers. The vulnerability demonstrates how seemingly benign components like graphics libraries can become attack vectors when not properly secured against integer arithmetic issues, emphasizing the importance of thorough input validation and proper boundary checking in all software components, particularly those handling user-supplied data.