Format string vulnerability in vsybase.c in vpopmail 5.4.2 and earlier has unknown impact and attack vectors. NOTE: in a followup post, it was observed that the source code used constants that, when compiled, became static format strings. Thus this is not a vulnerability

Buffer overflow in vsybase.c in vpopmail 5.4.2 and earlier might allow attackers to cause a denial of service or execute arbitrary code.

vpopmail 5.4.14 and 5.4.15, with cleartext passwords enabled, allows remote attackers to authenticate to an account that does not have a cleartext password set by using a blank password to (1) SMTP AUTH or (2) APOP.