CVE-2005-3946 in Web Browser
Summary
by MITRE
Opera 8.50 allows remote attackers to cause a denial of service (crash) via a Java applet with a large string argument to the removeMember JNI method for the com.opera.JSObject class.
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Analysis
by VulDB Data Team • 07/28/2017
The vulnerability identified as CVE-2005-3946 represents a denial of service weakness in Opera 8.50 browser software that stems from improper handling of Java applet parameters within the browser's Java Runtime Environment integration. This flaw specifically manifests when a malicious Java applet attempts to invoke the removeMember JNI method of the com.opera.JSObject class with an excessively large string argument. The issue resides in the browser's insufficient input validation and memory management practices when processing native method calls from Java applets, creating a scenario where malformed or oversized parameters can trigger unexpected behavior in the underlying Java Virtual Machine integration layer. The vulnerability operates at the intersection of browser security boundaries and Java applet execution environments, where the Opera browser's JavaScript Object interface fails to properly sanitize or limit the size of input parameters passed to native methods.
The technical exploitation of this vulnerability occurs through the manipulation of Java applet code that leverages the Java Native Interface to communicate with browser components. When the removeMember method receives a large string argument, the browser's JNI implementation lacks adequate bounds checking or memory allocation controls, causing the application to crash or become unresponsive. This behavior aligns with CWE-122, which describes improper restriction of operations within the bounds of a memory buffer, and represents a classic example of a buffer overflow condition that manifests as a denial of service rather than arbitrary code execution. The vulnerability demonstrates how Java applet security models can be bypassed through careful manipulation of native method calls, where the browser's trust in applet-provided parameters leads to system instability.
The operational impact of this vulnerability extends beyond simple browser crashes to potentially disrupt user productivity and create security concerns in environments where browser stability is critical. Attackers can reliably trigger the denial of service condition by embedding malicious Java applets in web pages, causing the affected Opera 8.50 browser to become unresponsive or terminate unexpectedly. This creates opportunities for persistent disruption of web browsing sessions and can be particularly problematic in enterprise environments where users rely on browser functionality for business operations. The vulnerability operates at the application layer and requires no special privileges or user interaction beyond visiting a malicious webpage, making it particularly dangerous as a vector for user experience degradation and potential service disruption. The attack pattern follows ATT&CK technique T1211 which describes exploitation of known vulnerabilities to cause denial of service in applications.
Mitigation strategies for this vulnerability focus on both immediate browser updates and defensive programming practices. The most effective solution involves upgrading to a newer version of Opera that addresses this specific JNI parameter handling issue, as the original version contains fundamental flaws in its Java integration layer that cannot be adequately patched through configuration changes. Organizations should implement browser security policies that restrict Java applet execution or disable Java support entirely when it is not required for business operations. Additionally, network-level controls such as web application firewalls can be configured to detect and block suspicious Java applet content that might attempt to exploit this vulnerability. The remediation approach should also include user education regarding the risks of visiting untrusted websites and the importance of keeping browser software updated to protect against known vulnerabilities in the Java integration components.