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Created March 11, 2026 12:40
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CVE-2024-34447: CVE-2024-34447: Hostname Verification Bypass in Bouncy Castle Java JSSE - CVE Security Report
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CVE-2024-34447.md

CVE-2024-34447: CVE-2024-34447: Hostname Verification Bypass in Bouncy Castle Java JSSE

CVSS Score: 7.5 Published: 2024-05-03 Full Report: https://cvereports.com/reports/CVE-2024-34447

Summary

A vulnerability in the Bouncy Castle Crypto Package for Java (BCJSSE) permits adversaries to bypass TLS hostname verification. By exploiting a fallback mechanism that evaluates the peer's IP address instead of the intended hostname, an attacker capable of DNS spoofing can conduct Adversary-in-the-Middle (AitM) attacks to intercept encrypted traffic.

TL;DR

Bouncy Castle JSSE < 1.78 incorrectly falls back to IP-based hostname verification when an explicit hostname is not provided during socket initialization. Attackers can leverage DNS spoofing to perform MitM attacks by presenting a valid certificate for the spoofed IP address.

Technical Details

  • CWE ID: CWE-295
  • Attack Vector: Network
  • CVSS Score: 7.5 (High)
  • EPSS Score: 0.00227
  • Exploit Status: No Public PoC
  • KEV Status: Not Listed

Affected Systems

  • Bouncy Castle Crypto Package (Java)
  • Bouncy Castle (LTS)
  • Bouncy Castle FIPS TLS (Java)
  • Bouncy Castle Crypto Package (Java): < 1.78 (Fixed in: 1.78)
  • Bouncy Castle (LTS): < 2.73.6 (Fixed in: 2.73.6)
  • Bouncy Castle FIPS TLS (Java): < 1.0.19 (Fixed in: 1.0.19)

Mitigation

  • Upgrade Bouncy Castle Java packages to patched versions
  • Explicitly configure socket hostnames using setHost() during custom implementations
  • Deploy DNSSEC to prevent malicious DNS resolution redirection

Remediation Steps:

  1. Identify all projects utilizing Bouncy Castle JSSE dependencies
  2. Update maven/gradle build files to require bc-java >= 1.78, bc-lts >= 2.73.6, or bc-fips >= 1.0.19
  3. Review custom HttpsURLConnection or SSLSocketFactory implementations to ensure explicit hostname binding
  4. Validate that endpoint identification enforces strict FQDN matching via code audits

References

Generated by CVEReports - Automated Vulnerability Intelligence

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