Re: patch for qpopper remote exploit bug

[deraadt () CVS OPENBSD ORG (Theo de Raadt)]

 Yeah, but what about systems that do _not_ have vsnprintf()?
 Using calls without bounds checks can be justified as long
 as it is made dead sure that no bounds would be ever exceeded.

You complain to your vendors.

This is a function which every vendor should have in their libraries.
If they don't, I can promise you that OS has not been audited, and
that 10 or so bugs in libc exist which will bite you.

Today, snprintf and vsnprintf are required.  Without them, there's
some code in the libraries which cannot be written safely.

ie:

gen/syslog.c:   prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);

Hmm.