Amazon Linux AMI Security Advisory: ALAS-2019-1327
Advisory Release Date: 2019-12-19 23:34 Pacific
idn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string. (CVE-2019-18224 )
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.(CVE-2019-12290 )
Run yum update libidn2 to update your system.