libidn2 -- roundtrip check vulnerability

2019-11-14T00:00:00
ID F04F840D-0840-11EA-8D66-75D3253EF913
Type freebsd
Reporter FreeBSD
Modified 2020-06-24T00:00:00

Description

CVE list:

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.