Buffer overflow in w3m 0.2.1 and earlier allows a remote attacker to execute arbitrary code via a long base64 encoded MIME header.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6725
http://www.securityfocus.com/archive/1/192371
http://www.debian.org/security/2001/dsa-081
http://www.debian.org/security/2001/dsa-064
http://mi.med.tohoku.ac.jp/~satodai/w3m-dev-en/200106.month/537.html
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000434