ASN.1 parsers have been the source of a decent number of exploits, producing a bad reputation. Although doing a little looking through CVEs that mention ASN.1,

ASN.1 parsers have been the source of a decent number of exploits, producing a bad reputation. Although doing a little looking through CVEs that mention ASN.1, it looks like the vast majority come from one specific ASN.1 parser, the one in OpenSSL, so it might just be that OpenSSL's code is a mess.