Re: EMERGENCY: new remote root exploit in UW imapd

From: Kragen (kragenat_private)
Date: Tue Jul 21 1998 - 09:36:06 PDT

  • Next message: Forrest J. Cavalier III: "Fast, efficient, limitless strings. In C."

    On Fri, 17 Jul 1998, Andy Church wrote:
    >      How many file races and symlink-following errors (for example) would
    > we hear about if programs were written in such a language?  Lots.
    
    True.  But the number of bugtraq postings would still drop by half, and
    the number of root-compromise holes would drop by perhaps a factor of
    three.
    
    Of course, buffer overflows are fashionable this year.  Perhaps next
    year it'll be something else.
    
    > (And if not, imagine the performance hit
    > when every array access has to be bounds-checked.  Security is good, but if
    > it drops performance into a tar pit you'll still have plenty of problems--
    > especially when your competitor is using a faster C program.)
    
    I've heard that bounds-checking typically increases the time to do
    things by 30-50%.  The bounds-checking egcs people are optimistic that
    this can be reduced.  Even so, it's much smaller than the variance
    introduced by different degrees of optimization and efficient design.
    
    Also, many security-sensitive programs are not speed-critical.  httpd
    nntpd, and mail servers are exceptions, of course, but finger, su,
    xterm, and the hundreds of other programs in which buffer-overflows
    have been recently found are not.
    
    >      I have to say that I've never programmed in Ada or Modula-2 myself
    > (and it's been years since I've touched Pascal, which I recall as being
    > similar to Modula-2), so I can't comment on just how appropriate they'd be
    > to server programs or deny that using such a language could improve
    > security.  But we won't get _truly_ secure programs until people can
    > program securely; and people that can program securely can write secure
    > programs in _any_ language.
    
    There have been proposals to require mechanically-verifiable proofs of
    certain security properties for secure programs.  This would increase
    development time, but would make it impossible to publish programs that
    did not have these properties.
    
    I think this is probably silly.
    
    Kragen
    



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