oss-sec mailing list archives

Re: CVE Request -- gpsd 3.9 fixing a denial of service flaw


From: "Eric S. Raymond" <esr () thyrsus com>
Date: Tue, 7 May 2013 21:30:01 -0400

Jan Lieskovsky <jlieskov () redhat com>:
Hello Eric,

  since there have doubts appeared:
    https://bugs.mageia.org/show_bug.cgi?id=9969#c2

Sorry, seem I missed some earlier mail, probably due to my DNS being
temporarily deranged after I upgraded to Ubuntu 13.04.  
 
which upstream patch has been the CVE-2013-2038 identifier assigned
to, could you confirm / disprove the latter?

* The true crash was in the NMEA(2000) driver, with upstream patch:
  http://git.savannah.gnu.org/cgit/gpsd.git/commit/?id=dd9c3c2830cb8f8fd8491ce68c82698dc5538f50

  This one should be referenced under CVE-2013-2038.

Not quite right.  The problem was with NMEA0183, not with NMEA2000.  But yes,
this crash has been seen in the wild, though not in conjenction with an 
identified attack.

* While the hypothetical one was in the AIS driver, with upstream patch:
  http://git.savannah.gnu.org/cgit/gpsd.git/commit/?id=08edc49d8f63c75bfdfb480b083b0d960310f94f

  Upstream 3.9 announcement "Armor the AIS driver against an implausible overrun attack."
  would support this.

Correct.  The potential AIS overrun has *not* been observed.  The
possibility was reported by someone reading the code.

Application of the patch looks reasonable. Just would be good to know
if it was applied just like a preventive measure (no DoS right now, just
prevent its [possible] occurrence in the future in case of code change)
or if under certain circumstances it might be used to DoS gpsd too?

It is a preventive measure.  I don't think it is presently exploitable,
but I'm not *certain* it isn't.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>


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