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Raccoon Attack on SSL/TLS

Raccoon Attack on SSL/TLS

Description

The Raccoon Attack (Raccoon vulnerability) is a timing vulnerability that affects the Diffie-Hellman key exchange used in SSL/TLS protocols. This attack allows an attacker to recover sensitive information by measuring the time it takes for a server to process certain cryptographic operations. Specifically, this vulnerability arises due to the way servers reuse Diffie-Hellman key shares across sessions, making it possible for attackers to derive information about the shared secret if they can observe and measure the server's responses over multiple sessions.

Key Security Impacts:

  • Sensitive Data Exposure: Attackers can potentially recover plaintext information from encrypted communications, compromising the confidentiality of the data.
  • Weak Session Security: If an attacker can observe enough connections, they may exploit timing variations to deduce encryption keys, making the session vulnerable to decryption.
  • Undermined Forward Secrecy: The reuse of Diffie-Hellman key shares weakens forward secrecy, allowing attackers to decrypt past sessions if they succeed in breaking one session.

Example Scenario:

  • An attacker eavesdrops on SSL/TLS connections over time and measures the slight variations in response times when the server handles key exchange computations. By using statistical analysis of the gathered timing data, they manage to recover part of the Diffie-Hellman key, which eventually allows them to decrypt sensitive data such as login credentials or financial transactions.

This vulnerability affects SSL/TLS implementations that reuse Diffie-Hellman key shares and do not have sufficient defenses against timing attacks.

Recommendation

To mitigate the risks associated with the Raccoon Attack, organizations should implement the following strategies:

  1. Disable Reuse of Diffie-Hellman Key Shares: Ensure that each SSL/TLS session generates unique Diffie-Hellman keys to prevent attackers from exploiting key reuse across sessions.

  2. Use Elliptic-Curve Cryptography (ECC): Adopt elliptic-curve-based key exchanges (such as ECDHE) which are less vulnerable to timing attacks and offer stronger security with shorter keys.

  3. Apply TLS 1.3: Upgrade to TLS 1.3 where feasible, as it uses more secure cryptographic algorithms and enforces forward secrecy, mitigating timing attacks like Raccoon.

  4. Reduce Timing Discrepancies: Implement constant-time cryptographic operations for key exchanges to minimize timing variations that could be exploited in side-channel attacks.

  5. Patch and Update SSL/TLS Implementations: Regularly update cryptographic libraries, such as OpenSSL, to the latest stable versions (e.g., OpenSSL 1.1.1 or later) where the Raccoon vulnerability has been patched or mitigated. Also, ensure that TLS stacks and software components are updated to the latest releases that address this and other potential vulnerabilities.

By following these steps, organizations can significantly reduce their exposure to the Raccoon Attack and strengthen the security of their SSL/TLS implementations.

Standards

  • SOC2_CONTROLS:
    • CC_6_1
    • CC_6_7
    • CC_7_1
    • CC_7_2
  • PCI_STANDARDS:
    • REQ_4_1
    • REQ_4_2
    • REQ_6_3
    • REQ_10_1
    • REQ_10_4
    • REQ_11_3
    • REQ_11_4
  • CCPA:
    • CCPA_1798_150
  • GDPR:
    • ART_24
    • ART_28
    • ART_32
    • ART_33
    • ART_34
    • ART_35
    • ART_77
    • ART_83
    • ART_82
  • CWE_TOP_25:
    • CWE_20
    • CWE_119
    • CWE_287
    • CWE_400
  • OWASP_MASVS_L1:
    • MSTG_CRYPTO_4
  • OWASP_MASVS_L2:
    • MSTG_CRYPTO_4
  • OWASP_MASVS_v2_1:
    • MASVS_CRYPTO_1
    • MASVS_CRYPTO_2