CVE-2017-5063 in Chrome
Summary
by MITRE
A numeric overflow in Skia in Google Chrome prior to 58.0.3029.81 for Linux, Windows, and Mac, and 58.0.3029.83 for Android, allowed a remote attacker to perform an out of bounds memory read via a crafted HTML page.
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Analysis
by VulDB Data Team • 09/17/2020
The vulnerability identified as CVE-2017-5063 represents a critical numeric overflow flaw within the Skia graphics library component that forms part of Google Chrome's rendering engine. This issue affects multiple operating systems including Linux, Windows, Mac, and Android platforms, demonstrating the widespread impact of the underlying memory management vulnerability. The flaw specifically manifests in the way Skia handles numeric calculations during graphics processing, creating conditions where integer overflow can occur and subsequently lead to memory access violations. The vulnerability was particularly dangerous because it could be exploited remotely through maliciously crafted HTML pages without requiring any user interaction beyond visiting the compromised website.
The technical implementation of this vulnerability stems from improper bounds checking within Skia's graphics rendering functions. When processing certain graphic elements, the library performs calculations that can exceed the maximum value representable by the underlying data types, resulting in a numeric overflow condition. This overflow corrupts memory boundaries and allows attackers to manipulate memory pointers to access regions beyond the intended buffer limits. The out of bounds memory read operation occurs when the corrupted calculations reference memory locations that are not properly allocated or accessible, potentially exposing sensitive data or enabling further exploitation techniques. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow and underflow conditions, making it a classic example of how mathematical operations can compromise memory safety.
The operational impact of CVE-2017-5063 extends beyond simple data exposure, as it provides attackers with a foundation for more sophisticated attacks within the Chrome browser environment. Remote exploitation through crafted HTML pages means that users can be compromised simply by visiting malicious websites, making this vulnerability particularly dangerous for general web browsing activities. The vulnerability could potentially be leveraged to extract information from memory, cause browser crashes, or even enable code execution in certain scenarios. Security researchers have mapped this vulnerability to ATT&CK technique T1059, which covers the use of command and scripting interpreters, as the compromised browser environment could be used as a staging ground for additional attacks. The cross-platform nature of the vulnerability also means that attackers could target users across different operating systems with a single exploit vector, significantly increasing the attack surface.
Mitigation strategies for CVE-2017-5063 primarily focus on immediate browser updates to versions that contain the patched Skia library implementation. Google released Chrome versions 58.0.3029.81 for Linux, Windows, and Mac platforms, and 58.0.3029.83 for Android, which address the numeric overflow conditions through improved bounds checking and integer overflow protection mechanisms. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive updates promptly. Additional defensive measures include browser hardening techniques such as enabling sandboxing features, restricting browser privileges, and implementing content security policies to limit the impact of potential exploitation. Network-level protections such as web application firewalls and intrusion detection systems can help identify and block attempts to deliver malicious HTML content that could exploit this vulnerability. The vulnerability also highlights the importance of regular security assessments of graphics libraries and rendering engines, as these components often represent significant attack surfaces that require continuous monitoring and updating to maintain security posture.