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Date: Thu, 23 Oct 2014 08:24:00 -0700
From: Michal Zalewski <lcamtuf@...edump.cx>
To: oss-security <oss-security@...ts.openwall.com>
Subject: Re: strings / libbfd crasher

> http://lcamtuf.coredump.cx/stringme

The immediate cause is due to srec_scan() in srec.c decreasing 'bytes'
without range checking until it wraps around. The already-bad value of
'bytes' is assigned to 'sec->size' few lines before the crash, so
perhaps there would be potential for exploitability later down the
line; but the code ends up crashing soon thereafter in a 'while (bytes
> 0)' loop that has no other exit conditions. That loop would need to
go over the entire address space without SEGV to avoid the crash.

/mz

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