Questions tagged [server]

A server is a machine running a software daemon that is generally accessed over a network by other machines.

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54
votes
5answers
59k views

Possible to use both private key and password authentication for ssh login?

It seems that they are mutually exclusive, as disabling one gives me the other, and vice versa. Two-factor auth for my ssh servers sounds really nice, so is there any way to accomplish this?
47
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13answers
42k views

DDoS - Impossible to stop?

Is it possible - in theory - to stop1 a DDoS attack of any size? Many people claim it's impossible to stop DDoS attacks and tell me I just shouldn't mess with the wrong people on the internet. But ...
45
votes
3answers
6k views

How do hosting providers prevent the compromise of one website from causing the compromise of another one?

Could one create a vulnerable website on purpose to attack a server of a hosting provider? So in the question above which I recently asked we came to the conclusion that preventing one vulnerable ...
41
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9answers
7k views

Is physical security less important with disks on a server being encrypted?

If you could get physical access to a server, you could change the root/admin password even if you did not know the current password. However with encrypted disks, I don't think this is possible (...
34
votes
5answers
8k views

Does changing an uploaded executable's file extension to .png render it safe?

A colleague of mine has a personal website in which he allows users to upload anything within a certain size, but before the actual upload he checks to see the file extension: if ( $type == 'image/...
30
votes
13answers
8k views

Is a server infrastructure fundamentally possible which the smartest person can't breach?

TL;DR: Perhaps I've gone overboard with my question's detail, but I wanted to be sure the question was clear since the topic seems very broad. But here it is. The word "smartest" is meant ...
29
votes
3answers
3k views

Does password-protecting a server's BIOS help in securing sensitive data?

I'm running a server of which I protected the BIOS with a password. One doesn't have to enter this password before booting, but before entering the BIOS setup. I just did this from routine. However, ...
28
votes
3answers
7k views

Could a VPS provider have access to the content of their users?

Could a VPS provider like DigitalOcean have access to the content of their users? In their terms of service they do not mention anything related to this question, but could they theoretically have ...
27
votes
2answers
42k views

Creating user specific authentication methods in SSH

I have configured sshd on an Ubuntu server to use key authentication and it is working fine. I had to disable password authentication for key authentication to work. Server is always accessed via ...
22
votes
6answers
2k views

Is it fundamentally possible to validate that an unmodified version of your client connects to your server?

I'm cross posting this question from Programmers.SE because I think it's equally on-topic here and would like to pose the question to this community as well. This seems like a programming question ...
20
votes
2answers
4k views

What are the negative aspects of creating fake security footprints?

My take on reducing the risk of being hacked on products and installation have often been to create false footprints. From my own experience, the servers I've spent most time (and hate) on hacking ...
19
votes
3answers
4k views

PHP malware on server - but helpless in identifying the malicious code

I am new to this community, so please forgive me if my question is stupid. I discovered that my server got hacked, and found several PHP files on it. I haven't been lazy and tried my best to ...
19
votes
5answers
8k views

Are duplicate SSH server host keys a problem?

I'm doing an assessment of a small network that is using a good bit of virtualization. They have cloned some of their linux machines after generating their SSH server host keys. So the servers all ...
18
votes
4answers
814 views

Global Blackout is a myth?

In order to shut the Internet down, anonymous claimed that putting-down the 13 root DNS servers of the Internet and therefore disabling the HTTP Internet, the most widely used function of the Web, ...
16
votes
3answers
8k views

What is the most secured SMTP authentication type?

Say you have to choose only one among the following authentication types for your own SMTP server: LOGIN, PLAIN CRAM-MD5 DIGEST-MD5 NTLM/SPA/MSN Which one would you recommend for optimal security? ...
16
votes
2answers
9k views

Why should the OPTIONS method not be allowed on an HTTP server?

Why should the OPTIONS method not be allowed on an HTTP server?
13
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1answer
2k views

Git server security

I want to install a Git server for my company. I'm able to get a Windows virtual machine. Now I've been asked to assess its security aspects. I'm lost on how to achieve this goal. As it is a Windows ...
12
votes
2answers
7k views

How to encrypt data on the server?

I have some data on the server (running Linux) which needs to be encrypted (company policy). This data is being served by an application running on this machine. Now I consider a few possibilities: 1)...
12
votes
4answers
7k views

Setting up a security CTF server

I'm looking for resources and information from people who have experience running hacking capture-the-flag challenges. To sum it all up in a simple one-sentence question: How do you set up a server ...
11
votes
5answers
810 views

Does naming sensitive things discreetly provide protection?

I had a job where a manager said he liked naming servers after places because if they were named descriptively e.g. "passwords database server" they become obvious targets. I sort of generalized this ...
11
votes
1answer
3k views

What is the difference between HSM and Key server?

As per PCI-DSS requirements, we have to use either HSM (Hardware Security Module), or Key Server to store the KEK (Key Encryption Key). If I'm storing encrypted DEK (Data Encryption Key) in an App ...
10
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2answers
3k views

Are hacked email addresses a local network or web server problem? [closed]

I work at a small nonprofit and woke up to find that many of our email addresses have been sending spam asking recipients to open an attachment (doc file). We have a local network that all of our ...
10
votes
3answers
343 views

What is a good source for hardened base configurations

I attended B-Sides in Orlando FL where one of the speakers had mentioned a site which contains hardened configs for popular services such as apache and postfix. The author of these configs is ...
10
votes
1answer
4k views

Check logs for Heartbleed exploit use?

According to articles such as the following, it's apparently possible to check logs for heartbeat requests matching the payloads described in the Heartbleed exploit. Is this something that any server ...
10
votes
1answer
711 views

Once established, are sockets on localhost secure?

Once a TCP socket has been established on localhost, and a connection made using accept, is it possible for a non-privileged user to intercept or modify bytes sent over this connection, or can this ...
9
votes
5answers
7k views

How To Prove That Client Side Javascript Is Secure?

Imagine that you have a web application that encrypts the user's data, such as a note or spreadsheet, on both the server and client. The normal process for a user using this web application is ...
9
votes
1answer
4k views

What are the privacy pros and cons of using a public DNS server vs. your own?

Whether I'm using a normal internet connection setup, or tunnelling it through an anonymizing VPN or through TOR, what information of mine is revealed to whatever DNS server that I choose (e.g. Google ...
8
votes
5answers
1k views

What Man-made Physical Threat Could Pose Severe Danger to a Server Farm?

I am writing a novel in which a researcher attempts to work against a study he is a part of by purposely sabotaging operations on the research compound. I am wondering if the following is plausible. ...
8
votes
1answer
476 views

Enterprise standard for securing servers.

This must be the most broad question to ask, but through the years, i've come up with my own list of things I so to secure my servers, I follow the obvious steps I could gather online such as, ...
8
votes
1answer
70 views

What are the recommended directory ownership & permissions for hosted websites?

So, I'm not sure what are the recommended directory ownership and premissions for directories of my websites. └── var └── www ├── website1 │   └── public_html └── website2 ...
8
votes
5answers
357 views

How can I ensure safety when literal passwords are required

I have a case at my hands where my server needs to make automated API calls that require authentication. Hence the server will need to know the literal passwords to make those calls. What options do ...
7
votes
2answers
8k views

How safe is the ownCloud encryption in a trusted LAN?

ownCloud looks like a promising locally hosted dropbox alternative. However, it has been pointed out that the encryption is not exactly strong... (The ownCloud team does at least provide a list of ...
7
votes
2answers
519 views

Could one create a vulnerable website on purpose to attack a server of a hosting provider?

Is it possible for a vulnerability in one application to be exploited to attack another application on the same server? So according to the answer to the question above it is possible that when one ...
7
votes
4answers
2k views

Authy: Does multi-device mode imply that all keys are stored on their servers?

My understanding is that if you use Authy, without backups/multi-device options, none of your account keys are stored on their servers. It all resides on your single device. Ie, even if Authy ...
7
votes
1answer
16k views

SSL Cert Types and Key Usage

I want to use OpenSSL to create a CSR and submit it to my CA (which uses Microsoft PKI) and receive certificates that can be used for both Server Auth and Client Auth. I'm not clear on a couple of ...
7
votes
1answer
807 views

How important is a mysql password for localhost?

We can assume that if an attacker gained access to a web server running mysql that they would be capable of reading the scripts to determine the mysql password. If mysql only responds on localhost, ...
7
votes
1answer
1k views

“Fix” man in the middle

I've just tried to ssh connect to a server (auth via ssh key), and get the well-known message WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!. I'm the server administrator (but I'm not really a good ...
7
votes
1answer
694 views

Are these SSH passwords of hacked servers?

I have been seeing persistent SSH connection attempts on my computer from a familiar IP address. I got curious and decided to do some Googling on the IP address. Turns out that someone from Indonesia ...
6
votes
4answers
45k views

How is HTTP PUT and DELETE methods insecure, if they really are? [duplicate]

If I really need to use these methods, how do i make sure they are secure? Edit: Is there a link or source where I can see how to make sure that 'PUT' and 'DELETE' methods are not able to delete or ...
6
votes
5answers
2k views

Bastion host that allows jailed users to SSH but protects private key

Basically, I'm trying to let the user use a private key without having read access to it. Use case: Employee needs to SSH to a server in the data center. There is 1 private key for all servers, ...
6
votes
2answers
4k views

Don’t use a web browser on a server?

After pulling up a Windows Server 2012 instance, I learned that google.com is riskier than I thought: It does the same for microsoft.com. There are instructions to disable "Enhanced Security ...
6
votes
1answer
2k views

How can one create one's own anti-virus scan server at home? [closed]

I suppose that every one used a service such as virustotal.com, anubis.iseclab.org, or any other service that could provide the same objective to scan same files. So my question is how can I make ...
6
votes
2answers
330 views

Could a fake tip that my server is compromised be a social engineering attack?

A little while ago I got the following email from an unknown party (using an @alum.cs.[redacted].edu email address): I'm seeing attack traffic from your Linode. Just a friendly heads up that its ...
6
votes
2answers
439 views

Secure Software: How to ensure caller is authentic?

For multiplayer (competitive) games, there is often the issue of needing to detect illegitimate players so they can be denied service. On the other hand, legitimate players should of course be ...
6
votes
3answers
4k views

How do I improve the physical security of a rack cabinet?

I've got an 8U 19-inch server rack cabinet with two locks - one on the front panel, one on the rear panel. The locks are small cam locks, but the cam part is rather thin and flimsy-looking. I could ...
6
votes
1answer
338 views

How to spare file server data from being held hostage by client ransomware?

Suppose in a network there is a file server which's storage is shared between all workstations and all users require full read/write access to this storage for their cooperation workflow. (Over samba, ...
6
votes
1answer
222 views

Browsers and HTTP Public Key Pinning

The strength of HTTP Public Key Pinning (HPKP) is that the browsers are saving the keys from the HTTP header and can check in the future if the certificate from the website is valid. I have two ...
6
votes
2answers
341 views

Will sabotaging a shared web hosting account threaten the security of sibling accounts being that they are shared on the same server?

Will sabotaging a shared web hosting account threaten the security of sibling accounts being that they are shared on the same server? Whether it it be through htaccess setups, posting login ...
6
votes
2answers
2k views

Restrict user from executing shell commands using PHP

Let's say that i have shared hosting and i want to secure that place, from executing shell commands. I'v installed suphp, so that users can execute PHP separately. I also did some other things in ...
6
votes
5answers
845 views

Does setting a default DROP policy actually improve security?

It seems that the status quo at the moment is to configure firewalls to drop any packets that aren't destined for specifically-opened ports. Many defensive port scanners (such as ShieldsUP!) seem to ...