I've been running my Google Compute VM for literally 1 day, and I was hacked, by this IP: http://www.infobyip.com/ip-121.8.187.25.html
I'm trying to understand what I can do next (user connected via ssh, root password was changed), to avoid these types of attacks (and to understand more than what /var/log/auth.log is telling me) ?
I assume you deleted the instance already, right ? from Developers console.
As suggested, always use ssh rsa keys to connect to your instance, instead of passwords. Additionally, depending on where you want access from, you can only allow certain IPs through the firewall. Configuring the firewall along with iptables, gives you better security.
You may also want to take a look at sshguard. Sshguard will add iptables rules automatically when it detects a number of failed connection attempts.
Just to make sure, please change the default port 22 in /etc/ssh/sshd_config to something else.
Related
following Problem:
I want to Check all Open MySQL Ports in a network and give myself a list of them.
After this i want to check if i can get access to the MySQL database from the open ports.
It Would be just a security check script to avoid other people getting access to the databases.
Bash/perl/Powershell... maybe someone can give me a hint?
You can use NMAP for all port scanning tasks.
EDIT:
Lets asssume an example: mysql-vuln-cve2012-2122(This vulnerability tries to access the MySql server through open ports by bypassing authentication, if possible, also dumps the MySQL usernames and password hashes.)
Pre-requisite: You need the 'Vulns' library to be installed separately. Please read the documentation, to know more about how to install and other details, since it would be too tedious to explain it here.
mysql-vuln-cve2012-2122.pass
MySQL password. Default: nmapFTW.
mysql-vuln-cve2012-2122.user
MySQL username. Default: root.
mysql-vuln-cve2012-2122.iterations
Connection retries. Default: 1500.
mysql-vuln-cve2012-2122.socket_timeout
Socket timeout. Default: 5s.
Please leave the password blank to check for non-password vulnerabilities.
Command to run:
nmap -p3306 --script mysql-vuln-cve2012-2122 <target>
Here is your MySql instance
This will give an output, something like this:
PORT STATE SERVICE REASON
3306/tcp open mysql syn-ack
mysql-vuln-cve2012-2122:
VULNERABLE:
Authentication bypass in MySQL servers.
State: VULNERABLE
IDs: CVE:CVE-2012-2122
Description:
When a user connects to MariaDB/MySQL, a token (SHA
over a password and a random scramble string) is calculated and
compared
with the expected value. Because of incorrect casting, it might've
happened that the token and the expected value were considered
equal,
even if the memcmp() returned a non-zero value. In this case
MySQL/MariaDB would think that the password is correct, even while
it is
not. Because the protocol uses random strings, the probability of
hitting this bug is about 1/256.
Which means, if one knows a user name to connect (and "root"
almost
always exists), she can connect using *any* password by repeating
connection attempts. ~300 attempts takes only a fraction of
second, so
basically account password protection is as good as nonexistent.
Disclosure date: 2012-06-9
Extra information:
Server granted access at iteration #204
root:*9CFBBC772F3F6C106020035386DA5BBBF1249A11
debian-sys-maint:*BDA9386EE35F7F326239844C185B01E3912749BF
phpmyadmin:*9CFBBC772F3F6C106020035386DA5BBBF1249A11
For more and detailed info, please refer the above link.
The NMAP tools will not only help you in getting the list of port related vulnerabilities. It can also be used to search for other vulnerabilities like MySql injection,DDOS, brute force vulnerabilities and lot more. Though you need to download separate libraries for those.
I have a hosted MySql server with many databases each with many views. I access the server remotely from my office using HeidiSql.
Once in a while the IP address of my office changes. When this happens, I have to add the new office IP address to the server using cPanel and the "Remote MySql" tool so that I can remotely connect again.
However, all of the views have definer: USER#OLD_IP_ADDRESS. If I need to change a view, I get Access Denied. Up to now, I have been deleting the view (yes, i can delete the view) and recreating it, which makes the view's definer USER#NEW_IP_ADDRESS, and then I can edit the view -- until the Ip address changes again.
So, my question is: What is the best practice is an environment like this. Is there a way to define the views once and, without causing a security risk, be able to edit the views after an IP Address change.
Thanks for any guidance.
You could loosen the host in the MySQL user account a bit, according to the IP range of your internet provider. That way, you don't need to change it every time you get a slightly different IP:
user#123.456.789.%
user#123.456.%
This of course loosens the security in this account, but if your password is be a good one, it should not be too risky.
A better way is to make the MySQL server only accessible via SSH. In that case, your MySQL server can be set up using the --skip-networking option, as you always connecting from localhost. Your user account can be user#localhost or user#127.0.0.1, which then would solve your above mentioned problem for all times.
HeidiSQL also supports SSH tunneled MySQL connections, see here for some tutorial.
I'm running EC2 with MySQL RDS to serve dynamic websites' content.
The server was down due to 'too many connection' error on RDS database.
As it was urgent, I restart database server straight away and the problem gone.
However, I'm unable to see what queries produce those connection (as I didn't run SHOW PROCESS LISTS before reboot RDS).
CloudWatch show 250+ connections during period of issue which is obviously huge distinction from normal operating on other days.
I try to address the issue by see log in RDS, but there is quite a minimal message there.
The error message
2014-05-03 06:10:08 3628 [Warning] IP address '173.244.206.19' has been resolved to the host name '173.244.206.19.static.midphase.com', which resembles IPv4-address itself.
From above, 173.244.206.19 is not in our IP list both public and private. (but connection open to 0.0.0.0 secured with password which I'm going to limit IP remote in security group soon)
Questions
Is 173.244.206.19.static.midphase.com is something to do with RDS by default. I think this is obviously an attack sign but just would like to confirm.
What does 'resembles IPv4-address itself' mean? As this is RDS database server only, why server does need to resolve DNS?
Are there any way to digging into this for further detail (e.g. to see specific query).
I'm going to prevent this by only limit the IP access along with CloudWatch alarm setting for 10+ connections. Anything else I should do.
Thank you for reading through this guys. I'm the only developer in company start-up which take care for all front-end/backend/application/network. Therefore, apology if there are dummy questions out here.
However, your help would be really appreciated and will save a bit of my life writing the report.
You are maybe the target of a DDOS attack or a brute-force password discovery attempt.
I would report this to AWS support - as they can help to mitigate the effect of the attack.
As a best practice, we do not recommend to use 0.0.0.0/0 as source IP address for incoming connection rule in Security Group.
Try to restrict which IP addresses are authorised to connect to your database.
If you are accessing from on prem network, specify only your on-prem address range.
If you're accessing your database from an app server installed on EC2, use the ID of the App Server Security Group (sg-xxxx) as source authorised to connect to your database.
I heard that anyone that knows my MySQL Username and Password can access it, Even if it's listening only to localhost.
Supposing my info is as following:
USER: root
PASS: 123456
Host: LOCALHOST (only)
How is it possible that anyone out there (local) can access it?
If you restrict access from remote hosts to your usernames and passwords then someone won't be able to access the database externally.
You could also configure your firewall to only allow traffic to 3306 (MySQL Default Port) from the localhost machine.
Update
To setup your user so they can only access through LOCALHOST use:
GRANT ALL PRIVILEGES ON *.* TO db_user #'localhost' IDENTIFIED BY 'db_passwd';
GRANT ALL PRIVILEGES ON *.* TO db_user #'127.0.0.1' IDENTIFIED BY 'db_passwd';
Also, bind your MySQL server to the local address. You can do this by editing the [mysqld] section of my.cnf:
[mysqld]
bind-address = 127.0.0.1
you can block direct access to MySQL at the firewall or within MySQL itself, but the most likely way you'd be hacked is through an insecure web application - in that situation the attacker would most likely be able to read your database login and connect from the server.
So keep your applications secure - keep everything updated, don't allow file uploads, use suPHP if you have multiple accounts etc.
If you restrict your mysql application follow this steps:
1.You could just block port 3306. If the site is on the same server then it will still be able to access the database using localhost as the hostname.
2.Just add "bind-address = 127.0.0.1" to the "[mysqld]" section of their my.cnf file to restrict access to localhost only.
Most of people use this type of restriction.
This is an older question that I stumbled across, but if Darkeden had phpMyAdmin or similar running, anyone can log in to that using valid MySQL credentials.
If it was compromised, then in addition to restricting connections, change all passwords.
I didn't see an answer that answered his (adjusted) question - he has locked it to localhost and the attacker is still getting in.
If you have truly restricted it to local host (check using netstat -an | egrep 3306 to check it is listening to 127.0.0.1 not 0.0.0.0),
then the only way of accessing it is to originate a connection from that local host.
Initial steps to take:
probably rebuild a replacement system from scratch and hardening it before you make it publicly accessible (having a repeatable recipe eg using ansible will help as you may have to go through a few iterations to learn how he gets in)
Check with reputable security scanners what you obvious holes are,
Get help from a security professional (depends if you want to spend $ or time and frustration to fix)
Apply security patches,
Remove services you don't need,
restrict the database access to only those programs that need it,
redo all your passwords,
check for installed root kits, and other viruses,
secure your server if at your own office and train staff in handling social engineering,
use a service that will monitor and filter the requests coming through and deny direct access (eg use cloudflare as a cheep starting point)
check for keyboard loggers (physical and software and other viruses) on all machines used to access the server),
check for physical means of logging your keystrokes in accessing your server (eg web cam style used in atm), the more exotic include sound (https://en.wikipedia.org/wiki/Acoustic_cryptanalysis), typing with a nearby wifi access point (eg https://www.schneier.com/blog/archives/2016/08/keystroke_recog.html)
Add an audit trail and monitor database activity to work out how he is getting through, but at least you need to do all the obvious securing first because otherwise he will just hop from one security hole to another
He could be also getting through using:
accessing via some program you are running (eg a web server) that is externally accessible and has a security hole that allows him to run arbitrary sql commands through its existing database connection - see https://www.w3schools.com/sql/sql_injection.asp
tricking some program he has access to from outside to proxy a connection for him to localhost:3306 (eg through a miss-configured network firewall on the machine)
tricking some program to run a local program (bash. mysql etc), and from there gaining access to the database - buffer overflows and other specially crafted data is a common issue to running arbitrary code
man in the middle attack on a connection that has legitimate access
bugs in a program that is automatically or manually processing data from outside, eg email, processing of postscript/pdf/any document with scripting processing - even viewing a text file can be dangerous - see https://www.proteansec.com/linux/blast-past-executing-code-terminal-emulators-via-escape-sequences/
social engineering a way through getting people to give you access
managing to get a hardware device attached to a computer that has access (how many people will pick up a "memory stick" lying in the work car park and check it out instead its a "programmable keyboard", and ALL computers trust keyboards!)
and then many more all the other sorts of methods I don't know, but those that are involved share ...
Just remember that you need to have practical security, I think xkcd says it just right: https://xkcd.com/538/
Problem
Users from other IPs on the (Windows XP) LAN suddenly cannot connect to my local MySQL server.
Background
I've set up MySQL on my local Windows computer so that other computers on the network have access to the root account. I've added each IP as a host for root. Up to some weeks ago, things worked flawlessly and I could connect to the server programatically and using various MySQL admin tools. Now, however, the MySQL server simply refuses connections from those IPs and I can't figure out why.
The network changes that I've done are: changing network card for two (of three) computers and fiddled around with MySQL settings. None of which should have caused this problem. I've tried adding a new user with all relevant hosts, but I get the same type of error:
MySQL Error number 1045 Access denied
for user 'root'#'shop' (using
passwords: YES)
The odd part is that the computer name, 'shop', is used instead of the IP. I don't know why.
Somehow, IPs seem to be resolved now and hostnames are used. Did you grant access to root#shop? Did you flush privileges?
First thing that pops into mind is Windows Firewall, which could have got re-enabled if you swapped NICs on the host computer.
My next suggestion would be to use a sniffer like Wireshark on the host computer and see what exactly happens packet-wise. You can use filters to make to reduce the output - they're very simple and easy to use. This tool has saved me countless hours of debugging.
-EDIT-
Another possible cause might be that your server somehow decided to resolve IPs to hostnames, in which case ip addresses may no longer work - one would need to add hostnames to the allowed list. Not sure if it works this way for MySQL though.
Could you have turned off TCP connections in MySQL?
Also, is the MySQL port open in your firewall?
If you changed your IP (DHCP?), make sure to correct it in my.cnf if you bound mysqld to your lan ip:
[mysqld]
...
bind-address=192.168.x.y