Secure testing team - Jul 2008 - Bug#491182: byacc: CVE-2008-3196: out of bound access

Package: byacc
Severity: grave
Tags: security, patch
Justification: user security hole

Hi

Quoting an email[0] from Jan Lieskovsky about CVE-2008-3196.

Description of problem:
======================
Otto Moerbeck has reported the following potential out of bounds of the
allocated stack access in the yacc binary:

Fix an venerable bug: if we''re reducing a rule that has an empty
right hand side and the yacc stackpointer is pointing at the very
end of the allocated stack, we end up accessing the stack out of
bounds by the implicit $$ = $1 action.  Detected by my new malloc,
experienced by sturm@ on sparc64; ok deraadt@

Public mention of this issue:
============================
http://marc.info/?l=openbsd-cvs&m=121553004431393&w=2

Proposed OpenBSD patch:
======================
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/yacc/skeleton.c.diff?r1=1.28&r2=1.29


When you fix this issue, please mention the CVE id in your changelog and upload
with high urgency, so
the packages reach testing quickly.

Cheers
Steffen

[0]: http://www.openwall.com/lists/oss-security/2008/07/15/3