CVE-2019-12290 : What You Need to Know

GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2, potentially allowing domain impersonation.

Understanding CVE-2019-12290

This CVE involves a vulnerability in GNU libidn2 that could lead to domain impersonation under specific conditions.

What is CVE-2019-12290?

The version of GNU libidn2 prior to 2.2.0 does not successfully carry out the roundtrip checks outlined in RFC3490 when converting A-labels to U-labels. This can result in one domain mimicking another, enabling the impersonation of arbitrary domains.

The Impact of CVE-2019-12290

Allows for the creation of harmful domains resembling targeted domains
Impersonation of arbitrary domains becomes possible

Technical Details of CVE-2019-12290

This section provides more in-depth technical information about the vulnerability.

Vulnerability Description

GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490 Section 4.2 when converting A-labels to U-labels. This makes it possible for one domain to impersonate another by creating a malicious domain that closely matches a target domain except for specific punycoded Unicode characters.

Affected Systems and Versions

Product: n/a
Vendor: n/a
Version: n/a

Exploitation Mechanism

The vulnerability can be exploited by creating a domain that closely resembles a target domain, exploiting the conversion process from Unicode to ASCII labels and vice versa.

Mitigation and Prevention

Protecting systems from CVE-2019-12290 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update GNU libidn2 to version 2.2.0 or newer
Monitor for any suspicious domain activities

Long-Term Security Practices

Regularly update software and libraries
Implement domain monitoring and verification processes

Patching and Updates

Apply patches provided by the vendor
Stay informed about security advisories and updates