CVE-2011-2628 in Web Browser
Summary
by MITRE
Opera before 11.11 does not properly implement FRAMESET elements, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via vectors related to page unload.
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Analysis
by VulDB Data Team • 06/13/2025
The vulnerability identified as CVE-2011-2628 affects Opera web browsers prior to version 11.11, specifically targeting the browser's implementation of FRAMESET elements within html documents. This flaw represents a critical security issue that stems from improper handling of frame-related structures during page lifecycle management. The vulnerability is classified under CWE-121 as a buffer overflow condition, though it manifests more specifically as memory corruption during the unloading process of web pages containing FRAMESET elements. Attackers can exploit this weakness by crafting malicious web pages that utilize FRAMESET structures in ways that trigger memory corruption when the browser attempts to unload these frames, potentially leading to arbitrary code execution or denial of service conditions.
The technical exploitation of this vulnerability occurs through the manipulation of FRAMESET elements in html documents, which are used to divide a browser window into multiple sections that can display different documents simultaneously. When Opera processes these elements and subsequently attempts to unload pages containing such structures, the browser fails to properly validate or handle the memory management associated with frame destruction. This improper implementation creates a scenario where memory corruption can occur, allowing attackers to either execute arbitrary code within the browser's context or cause the application to crash through denial of service attacks. The vulnerability specifically leverages the browser's handling of page unload events in conjunction with FRAMESET element processing, making it particularly dangerous as it can be triggered through normal web browsing activities.
The operational impact of CVE-2011-2628 extends beyond simple exploitation capabilities to encompass significant security risks for users of vulnerable Opera versions. This vulnerability can be exploited through various attack vectors including malicious websites, compromised web servers, or social engineering campaigns that direct users to specifically crafted pages. The memory corruption aspect of this vulnerability means that successful exploitation could allow attackers to execute code with the privileges of the browser process, potentially leading to complete system compromise if the browser has elevated permissions. Organizations and individuals using Opera versions before 11.11 face substantial risk, as this vulnerability can be exploited remotely without requiring user interaction beyond visiting a malicious website. The vulnerability's classification aligns with ATT&CK technique T1203, which covers exploitation of web browsers for privilege escalation and code execution.
Mitigation strategies for this vulnerability primarily focus on immediate browser updates to versions 11.11 or later where the FRAMESET implementation has been corrected. Security administrators should implement comprehensive patch management policies to ensure all Opera installations are updated promptly, as this vulnerability was specifically addressed through code changes in the browser's frame handling mechanisms. Additional protective measures include implementing web content filtering solutions that can block or warn users about potentially malicious FRAMESET usage, though this approach is less reliable as the vulnerability can be exploited through legitimate web content. Network security controls such as web application firewalls and intrusion prevention systems may provide additional layers of protection, though the fundamental solution remains the browser update. Organizations should also consider implementing security awareness training to help users recognize potentially malicious websites that might exploit this vulnerability, particularly in environments where browser updates cannot be deployed immediately. The vulnerability's resolution demonstrates the importance of proper memory management in web browser implementations and highlights the critical nature of maintaining up-to-date security patches.