2
votes
1answer
119 views

sudo still ask for password when NOPASSWD is used

I read all sudo posts on serverfault, but I still cannot figure out what I'm doing wrong. Normally I finally find the solution but not this time : I want apache user to be able to execute this ...
0
votes
2answers
32 views

If a web root directory has a simlink that points to a folder one-level up, does that pose a security risk?

Assuming a Linux/Unix system. Not asking about any particular server software, just wondering in general. I want to use this to include javascript libraries or things like that in multiple sites or ...
-1
votes
2answers
51 views

Security in users having sudo access

How to protect my passwords list (in different databases for example) in a UNIX environment where most of the users have sudo access to other user IDs? I have a script (main.sh) with the following ...
0
votes
2answers
78 views

Control IP to access a server , which use iptables

I would like to use linux command iptables to control to only allow the same subnet IP to access a server , what I would like to do is to allow any services from 10.168.1.0 to this server , could ...
-2
votes
1answer
50 views

Read a file created by root user on unix system [closed]

I have a file created by root user on unix system and the file is assigned to a particular group.All I want to do is read that file by logging in as user which is not root and not a part that ...
0
votes
1answer
342 views

Securing PHP's exec and others

I'm currently setting up an hosting service and, for now, i'm very concern about security. Here is my situation : I've set up multiple apache's vhost and for obvious securoty reason, i don't want to ...
0
votes
1answer
99 views

unix malicious scripts/ksh execution

I'm wondering whether my architecture poses a security risk. Details: The whole website is not ROOT owned but still, the APACHE user used instead has some pretty advanced permissions. I have a ...
1
vote
1answer
272 views

NIS: which mechanism hides shadow.byname for unpriviledged users?

On some Linux box (SLES 11.1) which is a NIS client I can do as root: ypcat shadow.byname and get output, i.e. some lines with the encrypted passwords, amongst other information. On the same Linux ...
7
votes
2answers
432 views

Password similarity

I wanted to change my password on a unix machine. I did a normal "passwd" and typed in my old and my new password. Then the machine came back to me with the following message: BAD PASSWORD: is too ...
4
votes
3answers
182 views

Store system passwords with easy and secure access

I'm having to handle several VPS/services and I always set passwords to be different and random. What kind of storage do you suggest to keep these passwords safe and let me access them easily? ...
3
votes
2answers
305 views

Solaris 11 installed, no updates?

I was messing around with solaris and decided to give Solaris 11 a try so I downloaded it from the Oracle website. After installing the OS, I went into the package manager and did an update. It told ...
-3
votes
2answers
290 views

Why is Windows often perceived to be more vulnerable to attack than other systems, such as Linux and Mac OS? [closed]

ok I need help on this question cause I am learning the computer, so I am try to understand the question.
2
votes
2answers
79 views

Disabling a compromised user account

I have a simple question for you, well, at least, much simpler than "How do I clean up a compromised user account?" The question is: "How do I disable a compromised user account?" There are some ...
2
votes
2answers
295 views

iptables (established, related rule)

I would like to know what the following iptables rule does exactly ? Why is it needed ? ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
0
votes
3answers
270 views

Nmap: what is the difference between “nmap <target>” and “nmap -sS <target>”?

This is an extremely basic question but also one I can't really seem to find an answer for, despite looking through the nmap documentation (man, online, and google). My question is, what is the ...
0
votes
2answers
1k views

Logwatch: Ignore certain IPs for SSH & PAM checks?

I have a CentOS 5.6 system, which runs Logwatch. If I perform a security scan (Nessus) against this host, it produces unnecessary noise in the Logwatch output. I'd like to run these security scans ...
2
votes
1answer
2k views

Why does nmap report different results from localhost?

When I execute "nmap -sT -O localhost" per the Centos 5 deployment guide, I get: Not shown: 1677 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 8080/tcp open http-proxy ...
0
votes
1answer
67 views

Groups & User Conventions for *nix Server

I'm looking for information on best-practices and common conventions for setting up users and groups for a unix-based web server hosting multiple sites. I'm looking for info on things like: how to ...
0
votes
2answers
194 views

Linux: Where are non-interactive commands logged?

As far as I know, when I SSH to a box, it will add my command history to something like .bash_history. But when I execute a command like rsync and it executes a remote SSH connection, rsync -avz -e ...
2
votes
1answer
694 views

Did anyone know about update in Bastille for unix/linux?

I'm just wonder that bastille project is still active or not? which alternative tools are proper for both unix and linux? Thanky you very much
0
votes
1answer
244 views

AIX /etc/security/user: what happens if the values in a stanza are specified twice?

I have an /etc/security/user file on AIX and I have a stanza that looks like this: someuser: expires = 0912154623 account_locked = false expires = 0116202437 account_locked = false Which of the ...
1
vote
3answers
110 views

UNIX-Security Advise

I want to build a quite secure UNIX-Server. Mechanisms I already implemented: SNORT + fwsnort for banning psad to block network-scanning attempts Portknocking to start+open SSH (key-based login - no ...
0
votes
2answers
61 views

mysql and unix users control

Let's say I have two users on my UNIX machine - user1 and user2. I also have two MySQL databases - db1(mysql_user1) and db2(mysql_user2). I want to prevent user1 from connecting to db2 even if it ...
4
votes
9answers
2k views

How can I test the security of my server?

How can I test the security of my server ? Please I know it is too general question. But I was wondering if there is a tester software or web service checking all ports of your server, or possibly ...
2
votes
2answers
454 views

CHMOD in web hosting

my Hosting is use Apache and PHP i understand what it's mean 777 in CHMOD or drwxrwxrwx or Owner, Group, Public => read, write, execute. i understand with the RW CHMOD command but what about the X, ...
1
vote
4answers
460 views

How to exploit data being written to file

I am trying to show that taking data as an input and writing directly to a file without parsing, checking or sanitizing it is a security risk. Can anyone show an example of how this can be exploited. ...
21
votes
10answers
4k views

I just did a chmod -x chmod

So I did a chmod -x chmod. How I can fix this problem? How do I give execute rights back to chmod?
0
votes
1answer
105 views

Samhain: depth of “-1”

In a samhainrc file you are allowed to have a depth associated with your dir. Like so: dir=3/etc/tinydns But what does it mean when you have a depth of -1? ( I was not able to find anything in the ...
3
votes
3answers
327 views

Linux Security/Sysadmin Courses in London? [closed]

My employer has offered to send me on a couple of training courses and I'm just looking for some recommendations. I'm mainly looking to improve my security and general sysadmin skills. I would like ...
0
votes
1answer
66 views

Users in ubuntu; Cant figure it out

I am the only one who will have access to my website. Just installed my VPS and managed to get most stuff working. However, stuck on the "members" part. Currently, everything has been done as ...
2
votes
2answers
607 views

Web Server Users - Best Practice

I was wondering what is considered best practice when several developers/administrators require access to the same web server. Should there be one non-root user with a secure username and password ...
4
votes
2answers
1k views

What is the secure way to isolate ftp server users on unix?

I've read documentation for various ftp daemons and various long threads about the security implications of using a chroot environment for an ftp server when giving users write access. If you read the ...
6
votes
6answers
4k views

Monitor the shell activity of a user on your Unix system?

Trust, but verify. Let's say I want to hire someone a sysadmin, and give them root access to my Unix system. I want to disable X windows for them, only allow shell usage (through SSH, maybe), so that ...
4
votes
6answers
446 views

Is it a good idea to encrypt files in unix?

There are (pdf) files placed under unix with 700 permission. The files contain sensitive data. Would it be a good idea to also encrypt these files? Would it make them any more secure?
2
votes
2answers
434 views

Using UUIDs for passwords

Does anyone have an opinion on using UUIDs as passwords? This is intended for accounts created for external users, such as customer access to private SFTP folders. Or are people using public key ...
1
vote
4answers
128 views

View logs of past logins to the server

I am using a server running the Debian operating system. Is there a way i can check who logged in to the server, i mean the past logins . I would like to do this to monitor the security on the server. ...
7
votes
5answers
405 views

I have about 20 servers…how do I manage the SSH keys and permissions of each?

I have database servers, web servers, SVN servers, etc. Often times I ssh among them...or they auto-ssh. How do I manage what server gets to log into which others?
0
votes
0answers
515 views

ssh on standard port 22: how risky?

I'm setting up a CentOS 5 machine that will be used by several coworkers. The only things it will be serving are ssh and Apache. I'm trying to assess the importance of running ssh on a nonstandard ...
2
votes
8answers
810 views

Alternative Linux Detection Methods To Detect A Compromised Host

This is a rewrite of my previous post as it was not entirely clear what I was trying to achieve. Hopefully this will make more sense :) In a nutshell what I am looking for is alternative methods to ...
3
votes
6answers
535 views

default ubuntu install, is it hackable?

Coming from a windows background, and I have admin'd a windows box for years now and I pretty much just have to install the patches (actually auto update takes care of that!). I am thinking about ...
6
votes
3answers
5k views

Tripwire and alternatives

I'm wondering if anybody could guide me here. I have 3 dedicated linux servers and want to install tripwire in order to track changes in the key files/folders in the filesystem Initial research has ...
3
votes
1answer
226 views

Flexible sudo access

I want to be able to give a user on a system I administrate the ability to access file X, using command Y using sudo. Is there a way to do this while allowing some flexibility over the arguments to ...
3
votes
6answers
3k views

How to add a linux user with a random or invalid password from a script

I want to add a user to the linux system from a script, but I don't want to invent or care for the password. This should be done automatically. The goal is to generate ssh-keys and this user needs ...
6
votes
5answers
1k views

Is there still a reason why binding to port < 1024 is only authorized for root on Unix systems?

On Unix systems, binding to tcp port < 1024 from a process without root privileged is denied. What was the initial reason and is it still valid ? For example http server don't need root ...
35
votes
2answers
4k views

Why do I have to edit /etc/sudoers with visudo?

I've noticed that the sudoers file and cron config files act in a special way compared to other config files on Linux. They need to be edited with a special wrapper rather than any text editor. Why is ...
5
votes
7answers
7k views

Should I use a login banner and if so, what should it say?

Are interactive login banners worth having? The general consensus is that they are, but what should the banner say? Some things that are being considered (no particular order): ownership of the ...
3
votes
7answers
634 views

Identifying changed files on *nix webserver

Looking for some (*nix) software which will build an index of "interesting" files on a server and notify when certain of those files contents are modified, or new files appear. Similar to rkhunter et ...
6
votes
3answers
2k views

Is SSH logging capabilities equivalent to su logging for private/public key authentication?

Here at work, we have a non-root shared login account on UNIX that is used to admin a particular application. The policy is to not allow direct logins to the shared account; you must login as yourself ...
5
votes
3answers
3k views

Directory that a user can read, but root can't?

There's a directory underneath my homedir called ".gvfs". As my regular user account, I can read it just fine: ~ $ ls -lart ~raldi/.gvfs total 4 dr-x------ 2 raldi raldi 0 2009-05-25 22:17 . ...
10
votes
8answers
3k views

Multiple *NIX Accounts with Identical UID

I am curious whether there is a standard expected behavior and whether it is considered bad practice when creating more than one account on Linux/Unix that have the same UID. I've done some testing on ...