probably omitted by mistake, but please keep the mailing list cc-ed.
On 10/24/10 3:38 PM, Sergey Okhapkin wrote:
Note that I check return code of www_authorize to be -1 (invalid user) and block IP in this case only. Other error codes should not block the IP address.
This one remembered me that in 3.1 we merged the auth modules and we used the one coming from ser because it has better nonce protection and other enhancements than kamailio version.
That means the return codes have changed, the new ones are listed now at: http://kamailio.org/docs/modules/stable/modules_k/auth_db.html#id2753068
Added also note in migration wiki page: http://www.kamailio.org/dokuwiki/doku.php/install:3.0.x-to-3.1.0#modules_k_a...
Cheers, Daniel
On Sunday 24 October 2010, you wrote:
I watched live an attack on voipuser.org while running 3.1 before release. It lasted 18 hours. I didn't want to ban it because was useful for testing and see if it reveals any weak. In most of the cases it hit pike module. I got some data and plan to make an article about it soon.
Anyhow, as a result of that, default config for kamailio has a section for detecting and banning such "bad" IPs, using pike to detect floods and htable to keep it blocked. Search WITH_ANTIFLOOD directive. It can be enhanced like you pointed here, so if the authorize fails, add the IP in the banned list stored in htable.
Using fail2ban together with IP tables has the advantage of dropping the packets before getting to application and eating cpu, although in the case of voipuser.org the cpu was not affected much - the rate was 170-200 requests per second.
Cheers, Daniel
On 10/24/10 3:06 PM, Sergey Okhapkin wrote:
I'm second for fail2ban. I block IP addresses with failed registration attempts for 1 hour. Here is my setup:
kamailio.cfg:
if (is_method("REGISTER")) { if(www_authorize("", "subscriber")< 0) { if($rc == -1) { xlog("L_INFO","Invalid username from $proto:$si:$sp\n"); sl_send_reply("200","OK"); } else www_challenge("", "0"); exit; } ....
/etc/fail2ban/filter.d/openser.conf:
[Definition] #_daemon = kamailio failregex = Invalid username from ...:<HOST>:
/etc/fail2ban/jail.conf:
findtime = 600
[openser-iptables] enabled = true filter = openser action = iptables-allports[name=OPENSER, protocol=all] logpath = /var/log/openser/openser # Replace with your sr log location maxretry = 10 bantime = 3600
On Sunday 24 October 2010, Uriel Rozenbaum wrote:
Juha,
I think we should be specially careful about black-lists. We receive many of these attacks in a per-day basis and a lot of them are from residential addresses or university, so I'm guessing some kind of worm or trojan performing the attack from various IPs.
If you have the time, try fail2ban deamon. It can relate some brute-force events and act accordingly blocking an IP on iptables, executing a script. You send to "jail" those addresses for a period of time, then you can get them out again; and of course you can manually revert.
Last, as a description of the attacks I saw, first it runs an NMAP like scan checking which IPs answer from 5060, then it starts sending registers (usually asterisk answers 404 if the user does not exist), then when the proxy challenges, it interprets the user is found and starts making dictionary attacks on the password (1234, admin, and so on). Keep safe complicated passwords, make kamailio challenge everything and you'll be safe. and again, fail2ban is a pretty good solution for brute force.
This might help you finding a solution for your attacks.
Cheers, Uriel
On Sun, Oct 24, 2010 at 8:54 AM, Juha Heinanenjh@tutpro.com wrote:
while doing some tests, i noticed that one of my proxies started to receive lots of register requests with different user names starting from a letter. there was also invite attempts in the logs. they came from ip 202.82.16.99 which according to traceroute is somewhere in china.
should we start publishing a black list of these attack ip addresses?
-- juha
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users