CVE-2018-6069 in Chrome
Summary
by MITRE
Stack buffer overflow in Skia in Google Chrome prior to 65.0.3325.146 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 • 06/06/2023
The vulnerability CVE-2018-6069 represents a critical stack buffer overflow flaw within the Skia graphics library component of Google Chrome browser. This issue affects versions prior to 65.0.3325.146 and demonstrates a classic memory corruption vulnerability that can be exploited remotely. The flaw resides in how Skia handles certain graphical operations during HTML page rendering, specifically when processing crafted HTML content that triggers improper memory access patterns. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the program stack. This particular implementation flaw occurs during the processing of graphical elements that utilize the Skia rendering engine, which is responsible for handling various visual components including images, text rendering, and vector graphics within web pages.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates opportunities for remote code execution and privilege escalation attacks. When a victim visits a malicious webpage containing crafted HTML elements, the Skia library's insufficient input validation causes a buffer overflow condition that can be leveraged by attackers to execute arbitrary code on the target system. The attack vector requires only a user to navigate to a malicious website, making it particularly dangerous in phishing campaigns or compromised websites. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1203 for exploitation for privilege escalation, as the successful exploitation can lead to full system compromise. The stack buffer overflow allows attackers to overwrite return addresses and function pointers, potentially redirecting execution flow to malicious payloads injected into the memory space.
The technical nature of this vulnerability stems from improper memory management within the Skia graphics library's rendering pipeline, where string operations and buffer allocations do not adequately validate input boundaries. The flaw specifically manifests when processing HTML elements that involve complex graphical rendering operations, particularly those involving text rendering or vector graphics transformations. Attackers can craft HTML pages containing malformed data structures that, when processed by Chrome's Skia component, trigger the buffer overflow condition. The vulnerability's severity is amplified by the fact that Skia is widely used across multiple Google products and platforms, making the attack surface significantly larger than typical browser vulnerabilities. This particular flaw demonstrates the inherent risks of complex graphics libraries in web browsers, where the combination of high-performance rendering capabilities and memory safety considerations creates potential attack vectors that can be exploited remotely without user interaction beyond visiting a malicious site. Organizations should immediately update to Chrome version 65.0.3325.146 or later to mitigate this vulnerability, as the fix addresses the underlying buffer overflow condition through proper bounds checking and memory allocation validation.
The broader implications of CVE-2018-6069 highlight the ongoing challenges in securing modern web browsers, which must balance performance requirements with security considerations. The vulnerability underscores the importance of proper input validation and memory safety practices in graphics rendering libraries, particularly those that are widely integrated across multiple applications. Security researchers and organizations should consider implementing additional monitoring and detection measures to identify potential exploitation attempts, as the vulnerability's characteristics make it suitable for automated exploitation in large-scale campaigns. The incident serves as a reminder of the critical role that graphics libraries play in browser security and the necessity of regular security updates and vulnerability assessments in complex software ecosystems.