CVE-2007-0012 in JRE
Summary
by MITRE
Sun JRE 5.0 before update 14 allows remote attackers to cause a denial of service (Internet Explorer crash) via an object tag with an encoded applet and an undefined name attribute, which triggers a NULL pointer dereference in jpiexp32.dll when the applet is decoded and passed to the JVM.
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Analysis
by VulDB Data Team • 08/03/2019
The vulnerability described in CVE-2007-0012 represents a critical denial of service flaw affecting Sun Java Runtime Environment version 5.0 before update 14. This issue specifically impacts Internet Explorer users who encounter specially crafted HTML content containing an object tag with an encoded applet. The flaw manifests when the applet is decoded and passed to the Java Virtual Machine, creating a scenario where the jpiexp32.dll component experiences a NULL pointer dereference. This particular vulnerability demonstrates how browser plugin components can become attack vectors when they fail to properly validate input parameters before processing them within the Java execution environment.
The technical root cause of this vulnerability lies in inadequate input validation within the Java plugin implementation for Internet Explorer. When an attacker crafts an object tag with an encoded applet and an undefined name attribute, the jpiexp32.dll module responsible for Java plugin operations fails to properly handle the malformed input. This failure results in a NULL pointer dereference, which causes the Internet Explorer browser to crash and terminate unexpectedly. The vulnerability specifically targets the plugin interface layer that bridges Internet Explorer with the Java Virtual Machine, making it particularly dangerous as it can be exploited through web-based attacks without requiring any local privileges or user interaction beyond visiting a malicious webpage.
From an operational perspective, this vulnerability creates significant security implications for organizations relying on Internet Explorer and Java applets for business operations. The denial of service attack can be executed remotely by simply hosting malicious web content, making it an attractive vector for attackers seeking to disrupt services or create distractions during more sophisticated attacks. The impact extends beyond simple browser crashes as it can potentially be used to disrupt business-critical applications that depend on Java applets for functionality, particularly in enterprise environments where Java plugins are widely deployed. Security professionals should note that this vulnerability operates at the intersection of browser security and Java runtime security, highlighting the complexity of securing plugin-based architectures.
Organizations should implement immediate mitigations including applying Sun Java Runtime Environment update 14 or later, which contains the necessary patches to address this NULL pointer dereference issue. Network administrators should consider implementing web content filtering solutions that can detect and block malicious object tags containing encoded applets with undefined name attributes. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping Java plugins updated. The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and can be mapped to ATT&CK technique T1211 which covers exploitation of vulnerabilities in software components. Organizations should also consider removing or disabling Java applets from web browsers where possible, as this addresses the root cause of the vulnerability while providing additional security benefits. The incident underscores the importance of maintaining up-to-date security patches and implementing comprehensive vulnerability management processes to prevent similar issues from affecting enterprise environments.