CVE-2007-3922 in JDK
Summary
by MITRE
Unspecified vulnerability in the Java Runtime Environment (JRE) Applet Class Loader in Sun JDK and JRE 5.0 Update 11 and earlier, 6 through 6 Update 1, and SDK and JRE 1.4.2_14 and earlier, allows remote attackers to violate the security model for an applet s outbound connections by connecting to certain localhost services running on the machine that loaded the applet.
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Analysis
by VulDB Data Team • 06/08/2025
This vulnerability exists within the Java Runtime Environment's Applet Class Loader implementation in multiple versions of Sun's JDK and JRE. The flaw represents a critical security bypass that allows remote attackers to circumvent the standard security model enforced by the Java sandbox. The vulnerability specifically affects versions 1.4.2_14 and earlier, 5.0 Update 11 and earlier, and 6 through 6 Update 1, creating a widespread impact across the Java ecosystem. The security model typically prevents applets from making outbound connections to localhost services, but this vulnerability enables malicious actors to establish connections to services running on the same machine that loaded the applet.
The technical flaw stems from improper handling of localhost connections within the applet security context. When an applet attempts to connect to a localhost service, the security model should enforce restrictions that prevent unauthorized access to machine resources. However, this vulnerability allows attackers to bypass these restrictions through specific connection patterns that exploit weaknesses in the class loader's network security implementation. The flaw specifically manifests when applets attempt to connect to certain localhost services, creating a pathway for attackers to access sensitive machine resources that should remain protected.
The operational impact of this vulnerability is severe as it allows remote code execution and privilege escalation within the target system. Attackers can leverage this flaw to access localhost services that may contain sensitive data, administrative interfaces, or system management tools. The vulnerability enables attackers to potentially gain access to databases, system services, or other localhost applications that are typically protected by the Java security model. This creates a significant risk for systems where applets are executed, particularly in enterprise environments where localhost services may be running with elevated privileges or contain confidential information.
Mitigation strategies should focus on immediate version upgrades to patched releases of the Java Runtime Environment, as this vulnerability was addressed in subsequent updates. Organizations should also implement network segmentation and firewall rules to restrict localhost access from applet execution contexts. The vulnerability aligns with CWE-284 Access Control Issues, specifically related to improper access control in network security contexts. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, as it enables attackers to execute commands through the compromised applet environment. Additionally, implementing strict network policies that prevent localhost service access from untrusted network contexts provides an additional layer of defense against exploitation attempts.