EUVD-2024-47107

Comprehensive Technical Analysis of EUVD-2024-47107

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Description: The vulnerability EUVD-2024-47107 affects the MatchDomainName() function in wolfSSL, where the input parameter str is treated as a NULL-terminated string without proper validation. The function X509_check_host() processes this input without ensuring it is NULL-terminated, leading to potential buffer over-reads.

Severity Evaluation:

• Base Score: 10.0 (Critical)
• Base Score Version: 4.0
• Base Score Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

The CVSS score of 10.0 indicates a critical vulnerability due to the high impact on confidentiality, integrity, and availability, combined with the ease of exploitation.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attacks: An attacker can exploit this vulnerability over the network (AV:N) without requiring user interaction (UI:N).
• Low Complexity: The attack complexity is low (AC:L), meaning it does not require specialized conditions or extensive knowledge to exploit.

Exploitation Methods:

• Buffer Over-Read: An attacker can craft a non-NULL-terminated string to cause the MatchDomainName() function to read beyond the intended buffer, potentially leading to information disclosure or crashes.
• Denial of Service (DoS): By sending malformed input, an attacker can cause the application to crash, leading to a denial of service.

3. Affected Systems and Software Versions

Affected Software:

• wolfSSL: Versions up to and including 5.7.0.

Affected Systems:

• Any system or application that uses wolfSSL for secure communications, including but not limited to:
  • Embedded systems
  • IoT devices
  • Web servers
  • Network appliances

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Patching: Upgrade to a patched version of wolfSSL that addresses this vulnerability.
• Input Validation: Ensure that all inputs to the MatchDomainName() function are properly validated and NULL-terminated.

Long-Term Mitigation:

• Code Review: Conduct thorough code reviews to identify and fix similar issues in other parts of the codebase.
• Security Training: Provide training for developers on secure coding practices, especially regarding string handling and buffer management.

5. Impact on European Cybersecurity Landscape

Impact Analysis:

• Widespread Use: wolfSSL is widely used in various industries, including critical infrastructure, making this vulnerability a significant risk.
• Regulatory Compliance: Organizations must ensure compliance with regulations such as GDPR, which mandates robust security measures to protect personal data.
• Supply Chain Risk: The vulnerability can propagate through the supply chain, affecting downstream products and services that rely on wolfSSL.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function Affected: MatchDomainName()
• Root Cause: Improper handling of user-provided input strings, assuming they are NULL-terminated without validation.
• Impacted Function: X509_check_host()

Exploitation Scenario:

1. An attacker crafts a non-NULL-terminated string.
2. The string is passed to the MatchDomainName() function.
3. The function reads beyond the buffer, potentially accessing sensitive data or causing a crash.

Mitigation Code Example:

void MatchDomainName(const char* str) {
    if (str == NULL) {
        // Handle NULL input
        return;
    }
    size_t length = strlen(str);
    if (length == 0 || str[length - 1] != '\0') {
        // Handle non-NULL-terminated string
        return;
    }
    // Proceed with the function logic
}

References:

• GitHub Pull Request

Conclusion: The vulnerability EUVD-2024-47107 in wolfSSL is critical and requires immediate attention. Organizations should prioritize patching and implementing robust input validation to mitigate the risk. The widespread use of wolfSSL underscores the importance of addressing this issue to maintain the security and integrity of European cyber infrastructure.