CVE-2007-5240 in JDK
Summary
by MITRE
Visual truncation vulnerability in the Java Runtime Environment in Sun JDK and JRE 6 Update 2 and earlier, JDK and JRE 5.0 Update 12 and earlier, SDK and JRE 1.4.2_15 and earlier, and SDK and JRE 1.3.1_20 and earlier allows remote attackers to circumvent display of the untrusted-code warning banner by creating a window larger than the workstation screen.
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Analysis
by VulDB Data Team • 07/27/2019
The vulnerability identified as CVE-2007-5240 represents a critical visual truncation flaw within the Java Runtime Environment that affects multiple versions of the JDK and JRE across different release lines. This security weakness specifically targets the display mechanisms of Java applications, particularly those involving security warnings and user interface elements that are designed to alert users to potential security risks. The flaw manifests when Java applications attempt to render user interface components that exceed the physical dimensions of the display screen, creating a scenario where security-critical warning banners may become visually truncated or obscured from view.
The technical implementation of this vulnerability stems from how the Java Runtime Environment handles window sizing and rendering operations when dealing with graphical user interface elements that surpass the boundaries of the physical display workspace. When attackers create windows larger than the workstation screen dimensions, the Java rendering engine's truncation mechanisms fail to properly display the complete warning banner, effectively allowing malicious code to bypass the intended security measures. This behavior creates a window of opportunity where untrusted code can execute without proper user awareness of the security implications.
From an operational perspective, this vulnerability significantly undermines the security model of Java applications by enabling attackers to circumvent critical user interface warnings that are designed to inform users about potential security risks. The impact extends beyond simple visual truncation, as it represents a fundamental failure in the security warning system that is intended to protect users from executing potentially harmful code. Attackers can exploit this vulnerability to deploy malicious Java applets or applications that would normally trigger security warnings, thereby reducing user awareness of security threats and potentially enabling successful social engineering attacks.
The vulnerability aligns with CWE-128, which addresses buffer overflows and truncation issues in user interface rendering, and relates to ATT&CK technique T1059.007 for Java-based execution. This weakness specifically targets the user interface layer of Java applications, making it particularly dangerous because it operates at the point of user interaction where security awareness is most critical. The vulnerability's exploitation requires minimal technical skill, as it only involves creating windows that exceed screen dimensions, making it an attractive target for attackers seeking to bypass security controls.
Mitigation strategies for this vulnerability primarily involve updating to patched versions of the Java Runtime Environment, as Oracle released subsequent updates that addressed the visual truncation issue in affected versions. Organizations should implement comprehensive patch management procedures to ensure all Java installations are current with security fixes. Additionally, administrators should consider implementing application whitelisting policies that restrict execution of unsigned or untrusted Java code, and deploy network-level controls to monitor and restrict Java applet execution in web browsers. The vulnerability underscores the importance of proper user interface design in security-critical applications and highlights the need for robust testing of edge cases in graphical rendering systems.