CVE-2013-0839 in Chrome
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 24.0.1312.56 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to the handling of fonts in CANVAS elements.
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Analysis
by VulDB Data Team • 04/22/2021
The CVE-2013-0839 vulnerability represents a critical use-after-free flaw in Google Chrome versions prior to 24.0.1312.56 that specifically targets the browser's handling of fonts within CANVAS elements. This vulnerability falls under the CWE-416 category of use-after-free conditions, where memory that has been freed is subsequently accessed, creating potential attack vectors for malicious exploitation. The flaw manifests when Chrome processes font data within canvas contexts, creating a scenario where an attacker can manipulate memory allocation patterns to trigger the use-after-free condition.
The technical implementation of this vulnerability involves the manipulation of font rendering operations within HTML5 CANVAS elements, which are commonly used for graphics rendering and image processing in web applications. When Chrome encounters certain malformed font data within canvas contexts, the memory management system fails to properly handle the deallocation and subsequent access of font-related memory structures. This particular attack vector leverages the browser's font handling subsystem, which is extensively used in modern web applications for rendering text and graphical elements. The vulnerability's impact extends beyond simple denial of service as it potentially allows for arbitrary code execution through memory corruption techniques that can be exploited to gain control over the browser process.
The operational impact of this vulnerability is significant for users of affected Chrome versions, as it provides remote attackers with the capability to either cause persistent denial of service conditions or potentially execute malicious code within the browser context. Attackers can craft malicious web pages containing specially crafted font data that, when rendered by the vulnerable browser, triggers the use-after-free condition. This could lead to browser crashes, application instability, or in more sophisticated attacks, full system compromise. The vulnerability affects the core browser rendering engine and is particularly dangerous because it operates at the level of graphics processing and font handling, which are fundamental components of web browsing experiences.
Mitigation strategies for this vulnerability require immediate patching of Chrome browsers to versions 24.0.1312.56 or later, which contain the necessary memory management fixes and safeguards against the use-after-free condition. Organizations should implement comprehensive browser update policies and maintain current versions of all web browsers to prevent exploitation of known vulnerabilities. Additionally, security professionals should consider implementing network-based protections such as web application firewalls and content filtering systems that can detect and block malicious font data patterns. The vulnerability demonstrates the importance of robust memory management practices in browser engines and aligns with ATT&CK technique T1059.001 for command and script interpreter usage, as exploitation may involve the execution of malicious code through compromised browser processes. Regular security assessments and vulnerability scanning should include checks for outdated browser versions to prevent exploitation of similar memory corruption vulnerabilities in the browser ecosystem.