snprintf(3c) redefined by libdb-1.85.4
| Description: | This idiotic library redefines snprintf() and vsnprintf() to ignore the length parameter! Thus any programs which use *nprintf() for bounds checking and link to libdb.so can be subverted! Sendmail may very well be vulnerable. |
| Author: | Thomas Roessler <roessler@guug.de> |
| Compromise: | subvert programs which use libdb.so |
| Vulnerable Systems: | Linux programs using libdb.so.1.85.4, as well as other versions. |
| Date: | 8 July 1997 |
Date: Tue, 8 Jul 1997 21:33:55 +0200
From: Thomas Roessler <roessler@guug.de>
To: linux-security@redhat.com
Cc: The mutt developpers' list <mutt-dev@cs.hmc.edu>, gertjan@cs.vu.nl
Subject: [linux-security] so-called snprintf() in db-1.85.4
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Hi,
There is a severe problem with the db-1.85.4 library's Linux
port that can be found on sunsite.unc.edu under
/pub/Linux/libs/db-1.85.4-src.tar.gz (sp?): This library
contains a "snprintf" function which breaks down to a common
sprintf, ignoring the size parameter. Obviously, this was
thought to be a terribly bad work-around for C libraries which
don't contain an snprintf routine of their own. The
consequences of this bug are obvious: Any program which is
linked with libdb.so.1.85.4 and relies on snprintf(3) to do
it's bounds checking doesn't have any bounds checking at all.
Note that recent linux C libraries contain an snprintf(3)
function of their own which does it's job properly. Thus, the
fix is to simply remove snprintf.o from libdb.
tlr
--
Thomas Roessler · 74a353cc0b19 · dg1ktr · http://home.pages.de/~roessler/
1280/593238E1 · AE 24 38 88 1B 45 E4 C6 03 F5 15 6E 9C CA FD DB
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