[scponly] How to protect against "chmod 777 /" ?

[Robert J Taylor]

Strange. I tried what you suggested and got the following:

psftp> chmod 777 /
set attrs for /: permission denied

I'm running scponlyc compiled on RH Enterprise Server 3.0 (using the RH9 
  changes).

The chrooted dir for user sftp is setup thusly:

	drwxr-xr-x    3 sftp  users        4096 Mar  2 03:58 public_html

User sftp is in group "users":
	[root at sftp1 root]# groups sftp
	sftp : users

Not sure what happened on your end...

Regards,

Robert Taylor

Lasse J. Kolb wrote:

> Hello!
> 
> Today I had a really strange thing:
> I have a chrooted user-account ... created a normal user, then used 
> scp-only.
> 
> Public-Key-Auth, and the chrootet home was:
> 
> /home/kai/
> 
> Then the user was able to do following:
> 
> He logged in with sftp and his key, and did: chmod 777 /
> 
> He was able to change the permissions of the chroot-dir!
> The next time he was not able to log in ... maybe because now 
> *anyone* could read/write/execute
> 
> And in sshd_conf the "scrict mode = yes" is set.
> Maybe that is, why he was not able to log on again.
> 
> How can I protect against this?
> 
> Lasse
-------------- next part --------------
A non-text attachment was scrubbed...
Name: robert.vcf
Type: text/x-vcard
Size: 255 bytes
Desc: not available
Url : https://lists.ccs.neu.edu/pipermail/scponly/attachments/20040302/d6af4d55/robert.vcf