CVE-2020-6525 in Chrome
Summary
by MITRE
Heap buffer overflow in Skia in Google Chrome prior to 84.0.4147.89 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability identified as CVE-2020-6525 represents a critical heap buffer overflow flaw within the Skia graphics rendering library that forms a core component of Google Chrome's rendering engine. This issue existed in Chrome versions prior to 84.0.4147.89 and created a significant security risk by allowing remote attackers to potentially exploit heap corruption through maliciously crafted HTML pages. The Skia library serves as Google's 2D graphics core and is responsible for rendering various visual elements including text, images, and vector graphics within web browsers, making it a prime target for exploitation due to its widespread use and complex functionality.
The technical nature of this vulnerability stems from improper bounds checking within Skia's heap memory management when processing certain graphical elements in HTML documents. When Chrome encounters specific combinations of HTML and CSS properties that trigger Skia's rendering path, the library fails to properly validate buffer boundaries during memory allocation and manipulation operations. This allows an attacker to write data beyond the allocated heap memory region, potentially corrupting adjacent memory structures and creating opportunities for arbitrary code execution. The flaw specifically manifests when the graphics library processes certain image formats or rendering commands that cause memory allocation patterns susceptible to overflow conditions.
From an operational perspective, this vulnerability creates a severe threat landscape for users of affected Chrome versions as it enables remote code execution through web-based attacks without requiring user interaction beyond visiting a malicious webpage. Attackers can craft HTML pages containing specially constructed graphics elements that trigger the buffer overflow when Chrome renders them, potentially allowing full system compromise. The attack surface is particularly concerning given Chrome's widespread adoption and the fact that exploitation can occur simply through normal web browsing activities, making it a high-value target for threat actors seeking to establish persistent access to user systems.
The vulnerability aligns with CWE-121 Heap-based Buffer Overflow, which specifically addresses buffer overflow conditions occurring in heap memory regions, and demonstrates characteristics consistent with techniques described in the ATT&CK framework under T1059.007 for Command and Scripting Interpreter. Organizations should prioritize immediate patching of Chrome installations to version 84.0.4147.89 or later, as this represents the first fixed release addressing the heap corruption issue. Additional mitigations include implementing web application firewalls, deploying content security policies, and utilizing sandboxing mechanisms to limit potential exploitation impact. Security teams should also monitor for indicators of compromise related to malicious web pages that might leverage this vulnerability, particularly focusing on unusual memory access patterns or unexpected browser behavior that could signal exploitation attempts.