Securing Linux systems and applications; understanding Linux security features.

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possible exploits through avahi daemon

It is always recommended to disable Avahi daemon, for security reasons, when not in use. So, by what ways it is possible to exploit a system which has avahi daemon service running? And how can we ...
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2answers
292 views

How to pass PCI DSS 2.0 anti-virus requirement (5.1) on Linux?

PCI DSS 2.0 Requirement 5.1 states: 5.1 Deploy anti-virus software on all systems commonly affected by malicious software (particularly personal computers and servers). This requirement ...
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3answers
811 views

Restrict access to a specific directory on Linux

I want to limit access to a single directory on the hard disk (log files) to few processes (log files for a single process for example). All processes run under the same user, so file system access ...
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4answers
376 views

What mechanism enforces user permissions in Unix/Linux?

One of the core pieces of security in Unix/Linux systems is limiting privileges by user. For instance, certain actions can only be done by the root user. In theory, this can keep a malicious process ...
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2answers
692 views

Possible implementations of networked+encrypted filesystem

Is it possible to implement scheme where remote server just share its filesystem (or resizable container file in it) and it's locally encrypted and mounted? And what is best practical method? (On ...
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2answers
305 views

Do LAMP log files sometimes contain sensitive information?

I will have a LAMP web server with CentOS and cPanel. With this setup, is it possible for any server log files, whether regular or error logs, to contain sensitive information in them, such as ...
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2answers
226 views

How likely is an infection with an outdated skype on linux? [closed]

Today I found an article about a skype hotfix and noticed that the repo I use on my linux notebook: deb http://download.skype.com/linux/repos/debian/ stable non-free Doesn't have the new version, ...
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2answers
1k views

/dev/random security holes

I'm doing some reading into the security issues surrounding /dev/random but it's proving to be hard to find good sources of information. Can anybody help? I've asked Google and got a bunch of articles ...
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2answers
728 views

What are the implications of including binary blobs in the Linux kernel?

According to this there are compelling reasons for caution when installing obfuscated binaries. Knowing this, how can running binary blobs as a part of the Linux kernel be acceptable from a security ...
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2answers
314 views

any reason not to run tmux/wemux on a bastion host?

Is there any reason to worry about running tmux/wemux on a bastion host? It seems to me that it would open up vectors to have your terminal sessions hijacked by some locally exploited account on the ...
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3answers
529 views

Truecrypt Plausible Deniability - Linux

As I understand it plausible deniability gives the user the option of having two passwords, one you provide the authorities/extortionist with and another that you might use for your self and files you ...
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1answer
172 views

Amavisd-New and Google safe browsing

I am studying the Google Safe Browsing. How do I know that it is possible to intercept a content of an email via amavis, I wonder if I can, for each url found, consult the Google safe browsing? Do ...
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1answer
1k views

Does the Ophcrack LiveCD require hash collection via programs like pwdump?

When I used the Ophcrack LiveCD recently, the program automatically ran without me manually loading any hashes. Question is: If Ophcrack does not automatically find hashes, how can I go about ...
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104 views

Protect partition from formatting

How can i protect my Linux and Windows partitions from being wiped,from a windows installation CD,with password?
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2answers
727 views

Restarting nginx with Jenkins or Phing - is it safe to allow Jenkins to run sudo without prompt for password

I am implementing the recommendations from Integrating PHP projects with Jenkins for my own PHP projects. I have created a jenkins user in my ubuntu 12.10 server. I used Phing as my build tool and I ...
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1answer
353 views

How do I configure Terminal Server (and clients) for use over untrusted Wifi networks?

Suppose a client wants to directly connect to Terminal Server exposed to the Internet, without a VPN, ... what software & settings is needed to properly protect against WiFi based attacks? ...
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1answer
80 views

auditing mod security rule sets

Is there a audit system that can help me try my strings? Such as user agents, post/get data, a simple way to test general sql injections to see how my rule sets hold? I know with fire fox I can ...
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2answers
371 views

Security for home server, wiki

I recently set up my own home server, running Ubuntu linux. The intent I'm having for this is to have a private wiki for my family, so we can have a place to collect information like phone numbers, ...
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1answer
451 views

Best method to sandbox X applications in ubuntu

What's the best way to sandbox an X application like firefox or thunderbird in ubuntu (going into the direction of what qubes os does, but only for single applications)? I know there are many ...
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4answers
180 views

One computer with multiple OSs in different drives

I use my personal computer for both programming work and gaming at my free time(and sometimes penetration testing) all these in different operating systems each. The problem is that I dont really ...
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1answer
143 views

Does reinstalling ubuntu eliminates all existing rootkits/ malware/spyware/ virus etc?

If I do a fresh installation of ubuntu from an uninfected cd, will it remove all the existing rootkits/malwares/spywares/viruses etc if any ? Is formatting the hard disk required before reinstalling ...
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2answers
793 views

Alternatives to SELinux and AppArmor?

With SELinux developed by NSA and AppArmor by Novell [*], what alternate solutions exists when trying to lock down a system and running applications, based on ACL and similar concepts like Zones on ...
3
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1answer
199 views

“WICKED” entries in the default nginx vhost's logs

I have a small VPS running nginx, and for a long time now (several months, since I rented it) it has been collecting weird entries in its default (listen 80 default;) vhost's logs: 109.x.x.121 - - ...
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2answers
1k views

What are the best IT auditing guidelines for Red Hat Linux 5.x+, including the critical data protection?

Currently, I am a junior application consultant and we are maintaining huge amounts of redhat machines as servers. I am given the chance and liberty by my boss (unbelieveable!) to go do my own ...
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1answer
1k views

ARP-poisoning on wireless network - no packets

I've started working with ettercap and ARP-poisoning; however, I've sumbled upon some problems. I've executed the following command: ettercap -i wlan0 -w log -T -M arp:remote /192.168.1.254/ ...
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1answer
495 views

Two questions about learning Linux exploit development fundamentals

getting ready to delve into the technical world of vulnerability assessment, and I have two questions about where to find certain information. First, I plan on reading "Understanding the Linux ...
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1answer
714 views

Firewall rules to block unwanted protocols on given ports

Does somebody has an idea, that what kind of iptables/pf rule must i use to achieve this?: i only want to allow these connections [on the output chain]: on port 53 output only allow udp - dns on ...
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1answer
70 views

Is a Linux environment PCI compliant if the swap file is not encrypted and PANs are loaded into RAM?

Is a Linux environment PCI compliant if the swap partition/file is not encrypted and PANs are loaded into RAM by an application?
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4answers
181 views

Find out what Linux software is trying to phone home

I have seen some suspicious outbound communications blocked on my VPS, which hosts a small experimental Web site, and want to find out which application is making the attempt. The server is running ...
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1answer
69 views

Does TRESOR protect against attacks like HeartBleed

I was wondering if the linux TRESOR module (http://en.wikipedia.org/wiki/TRESOR) would protect a webserver against HeartBleed or other similar attacks.
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1answer
122 views

SNMPv2 and Community Security

When working with servers on the internet and doing monitoring is there any dangers using SNMPv2? I am working with observium and have the following: /etc/snmpd.conf com2sec readonly default ...
3
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1answer
114 views

What about AD2P vulnerability?

My goal is to create a simple one-way intercom using B Speech TX2 and B Speech RX2, an Audio2Bluetooth and Bluetooth2Audio converter. My question is, how secure is the audio(in my case voice) being ...
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3answers
420 views

Proper Linux user authentication through PAM aware applications

Currently I'm building an authentication system using Linux PAM for a python daemon process. It will need to authenticate remote users from a variety of front-ends against the local user list. ...
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2answers
252 views

Safely remove an expired PGP key file

since it's possible to recover a deleted file I wonder how one can safely remove a PGP key file (with linux's command line tools) so that it's impossible to recover it. Maybe some dd command? Searched ...
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1answer
316 views

What are some steps to take for securing a Linux server that aren't in this list of obvious ones?

Obvious things: Disable root login (rather, don't enable it) Secure SSH (no root login, key auth only, timeout after inactivity, whitelist users who can SSH in, etc.) IP Tables firewall whitelisting ...
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1answer
135 views

Do public keys make Kerberos more secure (RFC4556)?

We're using IPA to centralize our authentication and I found an option to add a public key for each user. After doing a little research I found this to be an extension to Kerberos 5, RFC4556. From my ...
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1answer
252 views

How to forward an specific FTP User to a Honeypot?

What I'm trying to do is to forward a specific FTP-User to a Honeypot, because the main server is for Shared Hosting and there's a lot of traffic, and I don't want to spend all the resources in ...
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2answers
171 views

How do shared hosts protect different sites?

I host all my websites from a single VPN, and am about to sell some limited space of my Linode to a friend to host their new blog. It'll simply be another entry in Apache, and then a dedicated folder ...
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3answers
229 views

Protecting against Firewire DMA vulnerabilities in Linux

I know there have been questions on this in the past but they all seem quite outdated, or not that specifically relevant. I need to use a 1394(Firewire) connection, however am concerned with possible ...
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0answers
80 views

Deny Skype video access in Linux? [closed]

I have noticed that despite having configured Skype to not access video, during startups it continues to access the webcam momentarily. Skype is not a user, so I am unsure how to modify its ...
3
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1answer
885 views

Tacacs+ scenario: can I permit user to configure only for one interface and deny others

I'm currently deploying TACACS+ with a Cisco device, I use a TACACS server from here: http://www.shrubbery.net/tac_plus/ My scenario is: I want to permit a user to configure my router but only for a ...
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0answers
105 views

Apparmor policies w/ subprocess failing [closed]

Can anyone possibly explain why Apparmor is not picking up profiles for sub-processes of a process? Right now we use God to launch an unstoppable Ruby process (in this case it's /usr/local/bin/remote) ...
2
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2answers
271 views

vulnerable getlogin

I was reading "A taxonomy of Coding Errors" and I have a doubt regarding the point mentioned in C/C++ >> API Abuse >> Often Misused: Authentication(getlogin). I fail to understand the attack vector ...
2
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3answers
314 views

Is there an internal equivalent to fail2ban?

fail2ban is a protection against brute-force that locks a user out after a definable maximum failed login-attempts. But if a user already has access to a server with another username already fail2ban ...
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2answers
696 views

How to protect Linux partition from access from Windows partition?

In a dual-boot environment (windows? and linux mint 15) What would be best best way to prevent access to the linux partition(s) when the system is booted into windows 7? The goal would be to ...
2
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2answers
251 views

Can unencrypted keys & logins be kept out of program memory?

No matter what technique is used to store encryption keys & logins, it seems that all roads lead back to program memory (as far as I know), as an unencrypted version of the keys & logins will ...
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2answers
288 views

Can the `system` function pose severe security threats on a shared hosting server?

I recently bought an account from a shared hosting company and I needed the php system function to be enabled for one of my projects. So I created a ticket and asked them to enable it. This is what ...
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93 views

What kind of privacy leakage do stuff printed to stdout pose?

1- When a program outputs to stdout, is that normally logged anywhere else? 2- When is it an issue to make a command verbose in printing to stdout instead of working quietly or redirecting to a file? ...
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3answers
923 views

discover virus or spyware under Linux

I suspect to be the target of very skilled hackers. 5 or 6 years ago I found spyware on my Linux webserver, it was lkm masked as ppp_deflate module with md5 hash hijacked. I mean with the same md5 ...
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2answers
545 views

Allow apache to write to users' .ssh dir's

I know the title is just baiting the "your setup is insecure", but allow me to explain. I'm working on an application which aims to allow clients to rsync over SSH to our server. We need a web ...