CVE-2009-2121 in Chrome
Summary
by MITRE
Buffer overflow in the browser kernel in Google Chrome before 2.0.172.33 allows remote HTTP servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted response.
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Analysis
by VulDB Data Team • 04/06/2025
The vulnerability identified as CVE-2009-2121 represents a critical buffer overflow flaw within the browser kernel of Google Chrome versions prior to 2.0.172.33. This security defect resides in the core processing mechanisms that handle HTTP responses from web servers, creating a pathway for malicious actors to exploit the application's memory management systems. The vulnerability specifically affects the way Chrome processes incoming data streams, particularly when handling crafted HTTP responses that exceed allocated buffer boundaries. The flaw operates at the kernel level of the browser's architecture, making it particularly dangerous as it can potentially compromise the entire application execution environment. According to the Common Weakness Enumeration catalog, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The technical implementation of this flaw involves the browser's failure to properly validate the size of incoming HTTP response data before copying it into fixed-size memory buffers, creating predictable memory corruption patterns that can be leveraged for exploitation.
The operational impact of CVE-2009-2121 extends beyond simple denial of service scenarios to encompass potential remote code execution capabilities. When a malicious HTTP server crafts a response that exceeds the allocated buffer space, the overflow can overwrite critical memory segments including return addresses, function pointers, and other control data structures. This memory corruption can result in application crashes that manifest as complete browser termination, but more critically, it can allow attackers to inject and execute arbitrary code within the browser's execution context. The attack vector requires only that a user visits a malicious website or receives a crafted HTTP response through normal browsing activities, making this vulnerability particularly dangerous in real-world scenarios. The exploitability of this flaw aligns with ATT&CK technique T1203, which describes exploitation of software vulnerabilities for privilege escalation and code execution. The vulnerability's severity classification indicates that successful exploitation could provide attackers with the ability to execute malicious payloads with the privileges of the browser process, potentially leading to full system compromise through subsequent attacks.
Mitigation strategies for CVE-2009-2121 focus primarily on immediate remediation through software updates and system hardening measures. The most effective solution involves upgrading to Google Chrome version 2.0.172.33 or later, which includes patches specifically designed to address the buffer overflow conditions in the browser kernel. Organizations should implement comprehensive patch management protocols to ensure all affected systems receive updates promptly, as the vulnerability remains exploitable in older versions. Additional protective measures include network-level filtering to block suspicious HTTP responses, implementation of web application firewalls that can detect and prevent malformed responses, and browser security hardening through configuration changes that limit the application's attack surface. The vulnerability demonstrates the importance of robust input validation and memory safety practices in browser development, as outlined in industry best practices for secure coding standards. Security teams should also consider implementing monitoring solutions that can detect anomalous behavior patterns consistent with buffer overflow exploitation attempts, providing early warning capabilities for potential attacks targeting this vulnerability.