5
votes
2answers
272 views

Escalating from Apache shell to root

I have one noob question.I tried to exploit shellshock on my Slackware linux server, but after I connect with reverse shell and User Agent I get that I am apache user and apache user don't have too ...
2
votes
2answers
772 views

I ran a netstat on my server and port 80 is listening, does that mean it is open and vulnerable to attacks? [closed]

Sorry I am just getting into Web Development and trying to learn more about servers and PHP, so I downloaded the LAMP stack on an Ubuntu14 OS and started an apache2 server. tcp6 0 0 :::80 ...
2
votes
2answers
326 views

I've found security vulnerability in current linux distribution. What next?

I've installed ubuntu server 12.04 on VM two weeks ago. I've created regular snapshots. XXX time ago I've noticed unusual activity and I've found that a backdoor was installed into my server. One of ...
11
votes
4answers
512 views

How to react when under attack

Just this week someone has been trying to attack the server of the company where I work. I have noticed that they have been trying to brute force root via ssh. fail2ban is handling that well and I ...
0
votes
3answers
2k views

What is the hack attempt going on when I see: did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA

When I look at my sendmail logs, by far the most common "error" I see is the following: Nov 22 16:49:50 MyHostname sendmail[18832]: rAMMnj2u018832: [IP address redacted to hide the guilty] did not ...
-1
votes
2answers
148 views

Linux: Blocking outside attempts at attacking computer

in the past when I wanted to block outsiders from attempting to start connections with my Linux machine's various TCP services, what I was told to do was to add this line to /etc/hosts.deny: ...
-1
votes
1answer
237 views

If someone downloaded 600GB , can that be ddos attack [duplicate]

Last night some one exploit some vulnerability in my site and then upload php script in my images folder . I have the Amazon EC2 server with centos. Now the Hacker downloaded 600GB and increased my ...
3
votes
4answers
643 views

does switching to linux remove existing computer virus

if you change from a malware/spyware infected windows setup to a linux setup will infections migrate to linux if they were on the computer? (when you are hacked/infected is it the op system that is ...
5
votes
3answers
344 views

How I can prove that SSH attacks are not from my application?

My ruby on rails web application is hosted on Linode. Linode opened a ticket and blamed my Linode server for attacking other servers. The logs revealed that it's a SSH brute force attack which ...
2
votes
1answer
304 views

Bypass va_randomize_space and stack-protector

Is a program compiled with the GCC -fstack-protector option and running in a Linux environment with the va_randomize_space kernel variable set to 1, totally protected against buffer overflow attacks? ...
35
votes
4answers
5k views

Should I change the default SSH port on linux servers?

Is there any advantage in changing the SSH port, I've seen people do that, but I can't seem to find the reason why. If you have a strong password and/or a certificate, is it useful for anything? ...
0
votes
3answers
162 views

How to retrieve a site whose server is running Linux

I'm struggling to find a way to retrieve through Google a list of sites having Linux as their server operating system. Actually, I'd like to be able to test the following command: nmap -O ...
1
vote
2answers
759 views

How is iptables useful to prevent attacks against a LAN?

I need some advice securing a LAN using iptables. I've found lots of examples on how to secure single host with iptables, including scanning ports, attacking using ICMP-flood and TCP-flood. These ...
1
vote
1answer
5k views

How to use http-get-form in THC-Hydra?

I've been messing with Hydra (Brute Force) to solve the "Damn Vulnerable Web App" brute force section but the problem is when I use http-get-form it said: Warning: child 1 seems to have died, ...
9
votes
4answers
551 views

What would happen if one of the popular Linux repositories is hacked?

Even though most people consider downloading your Linux software from you own distribution's repositories as safe, thinking about the scenario where a repository gets hacked sounds thrilling. What ...
1
vote
0answers
256 views

Unauthorised Perl Scripts [closed]

One of my servers just had the memory exhausted by a load of Perl scripts, we use plesk and they seem to have appeared under the /var/www/vhosts/domainexample.com/cgi-bin/ directory, I managed to stop ...
7
votes
3answers
512 views

How to gain a shell?

I'm doing an exercise (exploit-exercises.com) that requires me to gain access to a shell running as another user. My question is this: I can create application that is guaranteed to be run by the ...
1
vote
1answer
1k views

How can log poisoning be successful with a Local File Inclusion attack?

I just read a paper about Local File Inclusion on exploit-db.com, it can be found here. One technique with LFI is log poisoning as you may know already. You do an HTTP GET request that contains PHP ...
4
votes
3answers
481 views

How do I protect myself against the attacks in this php script?

Due to a vulnerability in how PHP was installed (Shared VPS with PHP installed as an Apache module instead of CGI) and hence how OSCommerce was configured (with security of 777 on certain ...