CVE-2020-36477 : Vulnerability Insights and Analysis

An issue was discovered in Mbed TLS before 2.24.0 where the verification of X.509 certificates mishandles the matching of expected common names with actual certificate names, potentially allowing impersonation of domain names.

Understanding CVE-2020-36477

This CVE identifies a vulnerability in Mbed TLS that could be exploited by attackers to impersonate domain names by obtaining certificates for corresponding IPv4 or IPv6 addresses.

What is CVE-2020-36477?

The vulnerability in Mbed TLS before version 2.24.0 allows attackers to impersonate domain names by manipulating X.509 certificate verification.

The Impact of CVE-2020-36477

This vulnerability could lead to potential impersonation attacks, allowing attackers to present false certificates for specific IP addresses.

Technical Details of CVE-2020-36477

This section provides technical details about the vulnerability.

Vulnerability Description

When matching expected common names with actual certificate names, the verification process in Mbed TLS mishandles the comparison, potentially enabling impersonation attacks.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions Affected: All versions before 2.24.0

Exploitation Mechanism

Attackers can exploit this vulnerability by obtaining certificates for IPv4 or IPv6 addresses corresponding to domain names they want to impersonate.

Mitigation and Prevention

Protecting systems from CVE-2020-36477 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Mbed TLS to version 2.24.0 or newer to mitigate the vulnerability.
Monitor for any unauthorized certificates issued for IP addresses.

Long-Term Security Practices

Implement strict certificate issuance policies.
Regularly review and update certificate validation mechanisms.

Patching and Updates

Apply patches provided by Mbed TLS to address the vulnerability.