Improper Input Validation Affecting libidn2 Open this link in a new tab package, versions *

  • Attack Complexity


  • Integrity


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  • snyk-id


  • published

    23 Oct 2019

  • disclosed

    22 Oct 2019

How to fix?

There is no fixed version for Debian:10 libidn2.

NVD Description

Note: Versions mentioned in the description apply to the upstream libidn2 package.

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 in some circumstances for one domain to impersonate another. By creating a malicious domain that matches a target domain except for the inclusion of certain punycoded Unicode characters (that would be discarded when converted first to a Unicode label and then back to an ASCII label), arbitrary domains can be impersonated.