CVE-2011-3043 in iOS
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 17.0.963.65 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors involving a flexbox (aka flexible box) in conjunction with the floating of elements.
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Analysis
by VulDB Data Team • 04/13/2021
The vulnerability identified as CVE-2011-3043 represents a critical use-after-free flaw in Google Chrome versions prior to 17.0.963.65 that exposes users to potential remote code execution or denial of service attacks. This vulnerability specifically manifests within the browser's handling of flexbox layout properties combined with floating elements, creating a scenario where freed memory locations can be accessed after being deallocated. The issue stems from improper memory management during the rendering process when Chrome processes CSS flexbox layouts alongside floating CSS properties, leading to a state where memory addresses previously released to the system can still be referenced by malicious code. The vulnerability falls under the CWE-416 category of Use After Free, which is classified as a serious memory safety issue that can lead to arbitrary code execution when exploited properly.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious webpage that utilizes specific combinations of CSS flexbox and floating properties to trigger the memory corruption. When Chrome renders such content, the browser's layout engine processes the flexbox container and its child elements while simultaneously managing floating properties, causing the memory management system to free certain objects while still maintaining references to them. This creates a window where an attacker can manipulate the freed memory locations to inject malicious code or cause the browser to crash, resulting in denial of service conditions. The vulnerability demonstrates a classic memory safety issue where the application fails to properly track object lifetimes and memory allocation patterns during complex CSS rendering operations. According to ATT&CK framework, this vulnerability aligns with T1203 - Exploitation for Client Execution and T1059 - Command and Scripting Interpreter, as it enables remote code execution through browser-based attacks.
The operational impact of CVE-2011-3043 extends beyond simple denial of service scenarios, as the use-after-free condition can potentially be leveraged for remote code execution on vulnerable systems. Attackers exploiting this vulnerability could gain arbitrary code execution privileges within the browser sandbox, potentially leading to complete system compromise depending on the user's privileges and system configuration. The vulnerability affects all Chrome versions up to and including 17.0.963.64, making it particularly dangerous as it encompasses a significant portion of the browser user base at the time of disclosure. Organizations running affected versions face substantial risk of targeted attacks, especially in environments where users may encounter malicious web content through social engineering or compromised websites. The vulnerability's exploitation requires a sophisticated understanding of both browser internals and memory management, yet the widespread adoption of Chrome makes it an attractive target for cybercriminals seeking to maximize their attack surface.
Mitigation strategies for CVE-2011-3043 primarily involve immediate patching of affected Chrome installations to version 17.0.963.65 or later, which contains the necessary memory management fixes to prevent the use-after-free condition. System administrators should implement robust patch management policies to ensure all browser installations are updated promptly, as the vulnerability can be exploited remotely without user interaction. Additional protective measures include implementing web application firewalls to filter suspicious CSS content, disabling unnecessary browser features, and employing sandboxing technologies to limit potential exploitation impact. Organizations should also consider deploying browser hardening techniques such as disabling JavaScript for untrusted sites, implementing content security policies, and using privilege separation mechanisms. The vulnerability highlights the importance of continuous security monitoring and regular software updates, as even widely used browsers can contain critical memory safety flaws that require immediate attention to prevent exploitation. Security teams should also monitor for indicators of compromise related to this vulnerability, including unusual browser crashes or unexpected memory access patterns that may suggest exploitation attempts.