Content related to computer security., i.e. content about policies, mechanisms, etc. needed make sure data is not leaked or corrupted and services available in all circumstances.

learn more… | top users | synonyms

-1
votes
2answers
68 views

Is my system compromised or vulnerable to attacks

I ran netstat -lntup with the network connected. Recently one of my friends exploited my linux system using backtrack so I had to format it. Now I want to know whether I'm still being exploited or ...
3
votes
1answer
96 views

Has my machine been compromised?

I have a bunch of lines in my machine if I use "ps aux". Here are the lines: samp 8413 0.0 0.0 968 564 ? S 12:28 0:00 ./ssh 150 samp 8419 0.0 0.0 956 380 ? ...
3
votes
1answer
252 views

How do I change the Java Security level?

We've got an ancient (internal use only) self-signed app that refuses to run now with the changes to the JRE. Working on getting a code signing certificate and rebuilding it, but that's horribly slow ...
1
vote
2answers
152 views

What ports are essential and should generally be allowed on a Linux system?

I'm running a desktop computer, but one with high threat risk. I've blocked all ports using a firewall except: HTTP, HTTPS, DNS, one port for torrent client. Do any common processes in distros ...
1
vote
1answer
61 views

How can I protect my computer when the only way to access the internet is though a compromised internet connection?

I access the network through a connection which is most likely compromised by a MITM attack. I can't do much about it. What steps should I take to lessen the influence of this attack. I'm especially ...
0
votes
1answer
44 views

Is this method safe or recommended for moving a /home directory?

I have my linux install on a small disk. I want to put the home directory on a different hard-drive. I was thinking of using this and then this. Would this work? Is there a better way? Should I just ...
2
votes
1answer
2k views

How to Block SSH Brute Force via Iptables and How does it work?

I'm planning to add the following rules to iptables to stop ssh brute force attack which are common these days. -A INPUT -i eth0.103 -p tcp -m tcp --dport 4522 -m state --state NEW -m recent --set ...
2
votes
1answer
217 views

Reconfigure login through root ftp (lost ssh access)

My question is twofold. I need to somehow re-enable telnet and/or ssh in a device where I currently only have root ftp access. Also, if I am going about this wrong, please let me know. Details to ...
3
votes
1answer
178 views

How to disable root user on OpenBSD?

So there is a desktop and root permission isn't needed on it (or if it's needed, then reboot to single mode/whateverlivecd fix a config file-> get root, do the stuff with it and at the end, disable ...
2
votes
2answers
2k views

Why does sshd requires an absolute path?

Why does sshd require an absolute path when restarting, e.g /usr/sbin/sshd rather than sshd Are there any security implications? P.S the error message: # sshd sshd re-exec requires execution with ...
2
votes
1answer
166 views

Was my Unix server compromised?

Someone asked if this constituted a break-in and wondered if their server had been compromised. Jan 12 04:16:51 foo sshd[26725]: Failed password for root from 61.174.51.207 port 1076 ssh2 Jan 12 ...
0
votes
1answer
77 views

Break In Attempt

mysql service has vanished from my vps and service is down since yesterday where can see from /var/log/secure file it says break in attempt from an ip that is not known to me but cannot tell if the ...
4
votes
2answers
106 views

What are the methods to protect home folder files from other applications runing as the same user?

I would like to enforce the security access of some files in my Home folder. My concern is about processes running with the same privileges as me having access to those files. I've been wondering ...
3
votes
1answer
60 views

Run Windows program on Linux in a secure way

I am trying to find a way to achieve a secure execution of Windows programs inside a Linux installation. I suppose that a Windows malware should not do any damage (infect the machine), if executed ...
2
votes
4answers
287 views

Keeping my production webserver updated

I have a production webserver (CentOS 6.5) and I just wanted to know how do I keep this updated interms of security updates and stable. For example, is it safe interms of not breaking anything on the ...
5
votes
1answer
224 views

Secure access to remote SSH tunnel

So I wish to be able to access my Raspberry Pi (which I keep at home behind a firewall) remotely. One option is to use a static IP address, but as a poor student I don't want to fork out for one, and ...
1
vote
1answer
76 views

How to make my laptop safe & secure from any accidents like deleting by mistake?

This should be a general question. This Q sprung my mind yesterday late evening because I accidentally deleted files from another partition rather than from the partition I was intending to do. I'm ...
35
votes
9answers
3k views

How to trigger a system self destruct with a certain password is entered

How do I configure my system to destroy all personal data when a certain password is entered? The motivation behind this being NSA stuff. I imagine there being three primary usage cases. At login, ...
1
vote
1answer
74 views

SELinux and Trusted OS - can SELinux be confined to hardware level root?

I am exploring on SE Linux and while doing so i found it as an example of Trusted OS. Is it really an example of Trusted OS stack like TrouSerS ? SELinux as per my understanding modifies the Linux ...
1
vote
1answer
84 views

How to securely download rpmfusion keys

The Actual Problem I am trying to solve I am trying to automatically configure my fedora installations via salt to automatically have the rpmfusion repositories installed. In order to do this ...
3
votes
2answers
151 views

How to implement logwatch functionality on top of systemd journal?

Logwatch scans logfiles with regular intervals, collects errors and stuff, then mails it to the admin. This was back in syslog and logfiles days. What's the corresponding solution for systemd's ...
0
votes
2answers
103 views

Which runlevel is best for a Linux (Debian) server (DBMS/SCM)?

I currently try to harden the system and the security of a Debian server running a database and a source code management. I just want networking and me (one user) to be able to login. Which runlevel ...
2
votes
2answers
57 views

Securely viewing an encrypted file

I have a file that is gpg encrypted. I would like to view the content of the file, but leave no trace of the output. Lets say for example that the encrypted file has some passwords, and I don't want ...
2
votes
2answers
431 views

Is a -rw-rw-rw- file really inaccessible inside a drwxrwx— directory?

Say I have a directory with these permissions: drwxrwx--- Inside this directory, a file with these permissions: -rw-rw-rw- Is the file readable/writable by everyone or not ? If not, how secure ...
4
votes
1answer
239 views

Myth or reality: SELinux can confine the root user?

I read or heard somewhere (maybe in LinuxCBT's SELinux course; but I'm not sure) that there are online Linux servers, for which the password of the root user is also given. The Linux server is ...
4
votes
1answer
145 views

Is there any point in using `sudo` when you are the sole user of your machine?

I'd like to know if there is any reason why I should use sudo instead of su, taking into account that I am the owner and sole user of my machine (and hence have root access whenever I want). Also, in ...
1
vote
0answers
201 views

Unable to set capability CAP_SETFCAP by user

The question is about capabilities. I need to allow user to set capabilities using setcap. When I call it by root all goes fine, eg $ sudo setcap cap_dac_override,cap_dac_read_search+ep ./bin_file $ ...
1
vote
1answer
187 views

securely automating a script which requires a key to do its task

I have a script that downloads bank transactions to store in a database. To get these transactions requires a password for each account. The database is encrypted and requires a key to access it. All ...
2
votes
1answer
239 views

I need find 1 simple rootkit to test chkrootkit in centos?

I want to find 1 simple rootkit to test chkrootkit (a tool used to detect rootkit). Please recommend to me 1 rootkit and show me how to set it up or install it.
1
vote
1answer
105 views

Which software supports DoD 5220-22-M 7 pass standard for SLES 10.4?

"DoD 5220-22-M 7 pass standard" is a secure deletion method. But what software supports it for a SLES 10.4 64bit?
0
votes
3answers
355 views

noexec on /tmp and /var/tmp directory

Our client servers are running old version of jboss (Jboss 4.0) which has lots of known vulnerabilities. Result is that the server is hacked and we are seeing some unknown executables running from ...
5
votes
2answers
1k views

Setting ulimit correctly for PHP on Linux

I have /etc/security/limits.conf set to the following: nobody soft nofile 409600 nobody hard nofile 1024000 phpuser soft nofile 409600 phpuser hard nofile 1024000 httpd soft nofile 409600 httpd hard ...
6
votes
6answers
208 views

File protection in Unix

Is there a way to protect a file in such a way that even root cannot delete it or rewrite it after creating it? I have a file which is created by root under /var/log/ and I want to restrict all users ...
1
vote
1answer
170 views

Hidding an encrypted folder in a shared system without root access (unshare -m)

I'm a graduate student trying to use a cluster at my university. These machines are shared, so I want to protect the source code I use (I signed a NDA, so I'm scared about publishing the code by ...
61
votes
19answers
8k views

Root access that can't change root password?

We are having a little problem on a server. We want that some users should be able to do e.g. sudo and become root, but with the restriction that the user can't change root password. That is, a ...
2
votes
1answer
785 views

Securest way to authenticate users against /etc/shadow using PHP?

This question became important to me, since I'm setting up a Horde environment and want to use the system accounts. Doing some search I found mainly 4 ways of doing that, which all seem to have some ...
1
vote
4answers
209 views

How do I search for all the folders that begin with a dot ( . )?

My server had been infected and the attacker spread a bunch of .5randomletters folders around my file system, with malicious code inside of them. I want to search for all the folders that begin with a ...
8
votes
2answers
314 views

How can I create a hard to kill process

I want to create a program that will be difficult to stop (even for the administrator) once it is started (with root privileges). Once started the process should continue to start itself at startup ...
4
votes
2answers
185 views

Finding the logs in a hacked server. [closed]

My server has been hacked and the hacker managed to ssh as root (I know, horrible mistake on my part). What files should I be looking for to discover the origin of the attack? (At least their IP). ...
2
votes
3answers
102 views

How do I disable and re-enable Java whenever I want?

For me Java is just a security threat. Not many legitimate Linux apps use Java. However there is an abundance in Java malware and malicious remote administration tools like Jrat among others. But one ...
1
vote
2answers
176 views

How is the loopback device traffic allowed?

How can I allow the traffic to be sent on the loopback device (lo)? What is the iptables command for it?
0
votes
1answer
409 views

iptables couldn't load target allow

I am using the command below to allow all traffic from hosts on my internal network but it says "iptables v1.4.18: Couldn't load target `ALLOW':No such file or directory". What is the problem here? ...
5
votes
1answer
34 views

Need More Information About KDE Job Notification

I installed Debian 7.2 on a new laptop a couple of days ago, and now I'm getting a strange job notification every once in a while. It just says the following: Source: ...
1
vote
2answers
524 views

Is NFS very secure? Secure alternatives [closed]

I know that there is a very similar question to that Is NFS Secure Over Internet, but I am asking a little bit different. I guess that NFS is not so secure, as I can learn from the internet and from ...
4
votes
3answers
757 views

Running Viber as another user while using “mine” X Server's microphine and speakers

I run Fedora with GNOME and recently installed Viber for linux. It's very good and all is working just fine. As Viber is not open-source software, I decided to run it as another user to make sure ...
1
vote
0answers
220 views

How to secure Apache/MySql/PHPMyAdmin against brute force/dictionary attacks? (Fail2ban?)

I'm wanting to run a publicly accessible server for web hosting. I'm interested in preventing brute force attacks made against PHPMyAdmin or any other form of authentication process I may include in ...
3
votes
2answers
88 views

Is there any mitigation against touch date/time forgery?

I have been using touch -t to change time of a file when I started using Linux, is there any mitigation against touch date/time forgery? Like, echoing original created date and time, even after using ...
32
votes
4answers
1k views

Why can't I execute shutdown when the permission is rwxr-xr-x?

I'm in /sbin and I see that shutdown has permissions rwxr-xr-x. Doesn't this mean that anyone can execute it?
1
vote
5answers
176 views

Can I stop SElinux from working?

I suspect that SElinux is backdoor and I want to stop it from working on my system. I want to stop it and delete it from the system also if that is possible. Questions How can I delete it without ...
-1
votes
2answers
98 views

Is there any other way to restrict USB storage?

I have been using /etc/modprobe.d/blacklist.conf to restrict USB storage but all employees are given root permissions, so they are removing restriction very easily. What I'm looking for is is there ...