In this blog post, we will discuss about the CVE-2014-4263 vulnerability which has been found in Oracle Java SE versions: 5.u65, 6u75, 7u60, and 8u5, and JRockit versions: R27.8.2 and R28.3.2. The vulnerability is in the Diffie-Hellman key agreement process, which is a popular cryptographic algorithm used to securely share keys between two parties in a communication channel. This unspecified vulnerability allows remote attackers to affect the confidentiality and integrity of the data exchanged between the two parties by exploiting unknown vectors in the implementation of this key agreement protocol.

The Diffie-Hellman key agreement

The Diffie-Hellman key agreement is a widely used cryptographic algorithm that allows two parties, who do not have any prior knowledge of each other, to establish a shared secret key that can be used to encrypt and decrypt messages. This is done with the help of a public-private key pair, where both parties generate their public and private keys and exchange the public keys with each other. They then use their private keys along with the received public key to compute a shared secret key.

Code snippet of Diffie-Hellman key agreement implementation

import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.Security;
import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;

public class DiffieHellmanKeyAgreement {

  public static void main(String[] args) throws Exception {
    // Generate Alice's key pair
    KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("DH");
    keyPairGen.initialize(2048);
    KeyPair aliceKp = keyPairGen.generateKeyPair();

    // Generate Bob's key pair
    KeyPair bobKp = keyPairGen.generateKeyPair();

    // Create and initialize Alice's KeyAgreement instance
    KeyAgreement aliceKeyAgree = KeyAgreement.getInstance("DH");
    aliceKeyAgree.init(aliceKp.getPrivate());

    // Create and initialize Bob's KeyAgreement instance
    KeyAgreement bobKeyAgree = KeyAgreement.getInstance("DH");
    bobKeyAgree.init(bobKp.getPrivate());

    // Perform key agreement
    aliceKeyAgree.doPhase(bobKp.getPublic(), true);
    bobKeyAgree.doPhase(aliceKp.getPublic(), true);

    // Generate shared secret key
    SecretKey sharedSecret = aliceKeyAgree.generateSecret("AES");
  }
}

Exploit details

As mentioned before, the details of the exploit vector for this vulnerability are unspecified, meaning the exact way to exploit this vulnerability is unknown or has been kept confidential by the security researcher who found it. However, we do know that the attacker needs to have remote access to the communication channel between the parties using the Diffie-Hellman key agreement, and should somehow be able to manipulate or intercept the messages exchanged during the key agreement process in order to affect the confidentiality and integrity of the data being transmitted. This might involve a Man-in-the-Middle attack or injecting code into the targeted system.

Original references on CVE-2014-4263

1. CVE details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-4263
2. National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2014-4263
3. Oracle Critical Patch Update Advisory: https://www.oracle.com/technetwork/topics/security/cpujul2014-1972956.html

Recommendations and remediation

Oracle has released security updates for the affected Java SE versions and JRockit versions through their Critical Patch Update Advisory in July 2014 (link provided above). It is highly recommended to apply these security patches to your systems and also ensure that your Java applications are using the latest and most secure key agreement protocols available. Additionally, it is always a good practice to monitor your systems for any unusual activity and to implement strong security configuration practices to make it harder for an attacker to exploit any vulnerability.

Timeline

Published on: 07/17/2014 11:17:00 UTC
Last modified on: 05/13/2022 14:57:00 UTC