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.

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2
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1answer
19 views

How to scan a directory with a space in it's name with maldet

I'm trying to scan some directories with maldet: maldet -a /SOMETHING\ 1/ but I get: maldet(13857): {scan} invalid path /SOMETHING 1/ I've tried quoting the directory argument and can't think of ...
2
votes
2answers
855 views

AIX 6.1 — Without root can I get the last failed login for a user i have access to?

I know the information is in the security files but I don't have access and it's more work then I want to do to go to our Unix admins to get the information (everytime the account gets locked which is ...
2
votes
1answer
42 views

Exploit FOUND with clamav on Fedora 21 in Oracle's java

I'm scanning one of my systems with Clamav like this: $ clamscan -r -i --remove --max-filesize=4000M --max-scansize=4000M \ --exclude=/proc --exclude=/sys --exclude=/dev ...
1
vote
1answer
803 views

Any better alternative to chroot on an OpenVZ VPS?

Are there any better alternative to chroot environment? I'm thinking about running nginx on a jailed environment. BTW, I'm on OpenVZ VPS, so modifying the Kernel is a no-no. (I think that prevents ...
3
votes
3answers
73 views

Remove passphrase from private key and set specific file mode

If I set a passphrase on my private key like so: openssl rsa -des -in insecure.key -out secure.key and I remove the passphrase like so: openssl rsa -in secure.key -out insecure.key then my ...
1
vote
1answer
50 views

wheel groups and permissions

I'm new to a lot of things Linux, so this might be basic stuff. We're thinking about setting up a wheel group and removing permissions from root. Not even sure that's possible. We are having a ...
1
vote
1answer
359 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 $ ...
0
votes
1answer
24 views

Sanitise bash arguments

I have a script which takes user input and does a lot of things. One thing which I am worried about is it takes a file name and removes that file. e.g. rm -rf $arg1. A user could technically input / ...
5
votes
1answer
104 views

When running 'su - username', pam_group doesn't add additional groups from /etc/security/group.conf but sshd login does?

I am having trouble determining why su doesn't behave as the PAM configuration would imply. In short, using su to become another user should load secondary groups according to PAM configuration, but ...
4
votes
1answer
90 views

SSH server listening on multiple ports with passwordless access not allowing connections to second port

I have my Synology NAS running an SSH server listening on the default port 22 and I set up passwordless authentication with a public/private key and a passphrase: From sshd_config: ...
5
votes
2answers
419 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 ...
0
votes
1answer
26 views

How to import the official Tor GPG keys?

I am trying to install the latest Tor Browser Bundle on Arch Linux: $ makepkg --syncdeps --install [...] ==> Verifying source file signatures with gpg... tor-browser-linux64-4.0.8_en-US.tar.xz ...
1
vote
1answer
11 views

LDAP Force Password Change Through HTTPS

We have a "master" server running Suse Enterprise with LDAP that controls user's access to our systems. We want to implement a 90 day expiration policy, but the issue is that most of our servers are ...
0
votes
0answers
19 views

Bro-IDS CSV conversion

I have Bro-IDS currently operating under Centos 7. I need to convert the output to CSV format. The documentation that I have seen on this is not clear to me. Has anyone done this successfully? I have ...
1
vote
2answers
26 views

How do I install programs in /usr/local if they shouldn't be compiled by root?

Somewhere in the back of my brain is the memory of reading a cautionary internet voice warning against compiling (i.e. running make) as the root user. Perhaps it's something like this story ...
1
vote
1answer
66 views

Dubious entry in logwatch

Today I found the following in the daily logwatch of my debian server: --------------------- Connections (secure-log) Begin ------------------------ **Unmatched Entries** sg: user 'root' (login ...
0
votes
0answers
15 views

Snort alerts analysis (web interface)

I have a question about Snort (or maybe any other IDS/IPS, any working solutions would be ok). The goal is to set up some web interface providing a way to view the whole TCP stream packets of each ...
1
vote
0answers
6 views

Unable to use wifi card after putting it into monitor mode

I'm trying to monitor 802.11 Reauthentication requests and responses made from the DS to the STA. The problem is when using airmon-ng to put the card into monitor mode, the interface is no longer ...
45
votes
1answer
1k views

Security implications of forgetting to quote a variable in bash/POSIX shells

If you've been following unix.stackexchange.com for a while, you should hopefully know by now that leaving a variable unquoted in list context (as in echo $var) in Bourne/POSIX shells (zsh being the ...
62
votes
20answers
9k 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 ...
0
votes
2answers
35 views

FreeBSD 10 and ZFS: Methods for encrypting files

I'm in the process of setting up a FreeBSD 10 server on a KVM vserver. I'm really new to FreeBSD in general (coming from Debian Linux). I installed the system choosing ZFS with encrypted root volume ...
4
votes
2answers
3k views

How can I configure SELinux when the semanage command isn't found?

I'm having a very hard time configuring SELinux to allow Sending mail. Looking into selinux documentation I've found I can manage ports via the semanage command, but the command can't be found. Is ...
0
votes
2answers
51 views

SSH authenticity couldn't be established

Last night I SSH'ed to different systems.... one system/SSH reported that the "authenticity of HOSTNAME couldn't be established......." and it asks if I want to continue or something, I didn't and ...
6
votes
3answers
10k views

Moving /var, /home to separate partition

I am attempting to move some folders (such as /var and /home) to a separate partition after reading this guide: 3.2.1 Choose an intelligent partition scheme I was able to move one folder ...
2
votes
1answer
33 views

Are there any loopholes in IP restricting sshd?

Say that i want to only allow username/password logins on my private network, but restrict all external sources on to key/cert login. I would do something like this: RSAAuthentication yes ...
3
votes
1answer
129 views

CUPS and printer security

I would like some help on securing a networked printer. Specifically, I'm interested in the following: Preventing unauthorized access to the printer: I would like only certain laptops that connect ...
2
votes
2answers
42 views

Encrypted FileSystem in VirtualBox

I'm looking for any information regarding how secure an encrypted Linux file system is when contained in a VirtualBox virtual drive on a Windows host? Specifically I'm looking for answers to the ...
2
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0answers
5 views

Tails OS:Network Filtering Syntax to Allow I2PBrowser to listen at localhost:6666, Then Allow TorBrowser User to Connect to it

I've had a bit of experience in Linux, but I'm still learning and brand new. I've been able to proxy Tor right into I2P on a normal Debian Wheezy installation successfully. My process involves ...
7
votes
0answers
38 views

D-Bus authentication and authorization

I'm trying to set up remote access to D-Bus, and I don't understand how authentication and authorization are (not) working. I have a D-Bus server listening on an abstract socket. $ echo ...
5
votes
1answer
488 views

gdm greeter configuration: Exclude all *except* for one specific user

I have Googled this one and tried so many combinations, with no success. I need the GDM login greeter to display one and only one username. In effect, what I need is something like this in ...
0
votes
1answer
73 views

Is my server being used as a proxy or malicious requests?

I have an Ubuntu, Apache, Passenger, and Rails 4 project on AWS EC2. I am a beginner full stack developer and am unfamiliar with the security and server side of my project. This is my first time ...
0
votes
1answer
24 views

rkhunter warning about ssh root access when that access is not allowed on the system

I just ran rkhunter --check and all was good except this: Checking if SSH root access is allowed [ Warning] What does this warning mean? SSH root access is not allowed on this ...
17
votes
3answers
8k views

How can I determine if someone's SSH key contains an empty passphrase?

Some of my Linux & FreeBSD systems have dozens of users. Staff will use these "ssh gateway" nodes to SSH into other internal servers. We're concerned that some of these people use an unencrypted ...
2
votes
1answer
22 views

NOEXEC and RESTRICT in sudoers

I understand the script below has a serious problem, and NOEXEC and RESTRICT are not enough as a solution to this. user ALL=(ALL) /usr/bin/vim /etc/httpd/confs/httpd.conf However, I still have some ...
72
votes
6answers
43k views

Allow setuid on shell scripts

The setuid permission bit tells Linux to run a program with the effective user id of the owner instead of the executor: > cat setuid-test.c #include <stdio.h> #include <unistd.h> int ...
0
votes
0answers
49 views

Is my webcam driver being used to hack my computer?

I'm seeing this in the journal: Mar 27 14:01:02 user-PC gdm-Xorg-:0[424]: (II) Using input driver 'evdev' for 'TOSHIBA Web Camera' Mar 27 14:01:02 user-PC gdm-Xorg-:0[424]: (**) TOSHIBA Web Camera: ...
5
votes
2answers
411 views

How are mutually untrusted app's files protected in Linux

I am running a Ubuntu Linux machine. When I run applications written by different vendors like Chrome and Firefox, I notice that they all are running with my uid. But if that's the case, any file they ...
2
votes
2answers
411 views

RHEL 7 (CentOS 7) security / ssh / sshd_config advise requested

I am not a sysadmin and try to create a more or less secure web server (LAMP based CentOS 7). I read several tutorials about setup an initial CentOS 7 droplet and got everything running fine. ...
6
votes
1answer
3k views

What happens when your password expires and you're using key authentication?

on one of the boxes I don't control at work I use ssh keys to log in. Our passwords are set to expire after a few months. What happens if I don't reset my password and it expires? will I still be able ...
1
vote
1answer
33 views

Monitoring tool without web interface

I need to monitor a Linux server. I'm searching for a monitoring tool able to store system information (CPU, RAM disks usage, Apache and Postfix status, etc.) throughout the day and send an email ...
1
vote
1answer
543 views

Make bluetooth device invisible / disable incoming pairing

I am using the bluez package for my bluetooth usb dongle on ubuntu server. I want to be able to initiate bluetooth connection from the dongle to a device, however a device itself shall not be able to ...
2
votes
2answers
57 views

Per user tmpfs directories

Using the shared /tmp directory is known to have lead to many security vulnerabilities when predictable filenames have been used. And randomly generated names aren't really nice looking. I am ...
0
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0answers
13 views

Is user/filesystem access separation of services enough to have well secured data of services?

I'm about to publish some of my projects. So, I'm gonna to re-install my VPS and do it properly. I'll have running on it Apache server(websites are made using Ruby and Python), databases. I'll also ...
1
vote
1answer
36 views

How do I run a program without network access? [duplicate]

I am making a program that scrapes information from some web services. I want to test how my program reacts when it can't reach the web service, like if the web service is down or if the local ...
0
votes
1answer
38 views

unknown command “vftovp” in linux command history [ Is my linux box compromised? ]

I have Slackware linux system configured with ssh remote access. While observing the command history, I discovered that there is one unknown command executed from my linux box "vftovp". I certainly ...
10
votes
2answers
205 views

A consistent and safe approach to passwordless accounts with SSH

I must admit that I like servers without passwords in some cases. A typical server is vulnerable to anyone who has physical access to it. So in some cases it is practical to lock it physically and ...
0
votes
0answers
21 views

why do we have same chains in different tables of “iptables firewall” in linux?

why do we have same chains in different tables of "iptables firewall"? Like for example: we have "output" chain in filter table, nat table & mangle table.
3
votes
0answers
54 views

Is there a technical reason why ssh-agent lacks a sudo-like inactivity/idle timeout feature?

There are some brief discussions about the existing ssh-agent -t feature at [1], and there was a post as far back as 2001 on debian-devel [2] wishing for an inactivity timeout feature. There's a ...
1
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0answers
19 views

Are External API's secure? [closed]

I'm new to java. So please someone explain me if we can use external API's in my work? Are they secure to use?
10
votes
6answers
45k views

How can I monitor all outgoing requests/connections from my machine?

My machine is a server so I want to ignore connections being made to my server (e.g. when someone visits my website). I want to see only connections/requests being made by my server to other places. ...