CVE-2026-42521 Jenkins插件任意对象实例化漏洞

// Conceptual PoC demonstrating the configuration modification // This is not a direct exploit script but shows the vulnerable mechanism. // Attacker modifies the configuration XML (e.g., config.xml) to include: // <inheritanceStrategy class="java.io.File"/> // or a class available on the classpath that performs a sensitive action in its constructor. // Example Groovy script to simulate the vulnerable instantiation: try { // The vulnerable code effectively does this: def clazz = Class.forName("java.io.File"); // Arbitrary class def instance = clazz.getConstructor().newInstance("/etc/passwd"); // If constructor requires args, it might fail, but parameterless constructors are the target. // Real exploitation relies on finding a parameterless constructor that does something dangerous. // e.g., a logging class that dumps context, or a utility class that initializes system properties. println("Instance created: " + instance.getClass().getName()); } catch (Exception e) { e.printStackTrace(); }