Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [security]

Security covers a wide-ranging set of topics including Users, Permissions, Authentication, Authorisation, Upgrades, Firewalling, Hardening, etc.

0
votes
0answers
31 views

Can I login to any Ubuntu OS as root user with no password? [duplicate]

I mean can I login using Advanced options -> Recovery Menu as root user without any restriction (except for a Full Disk Encrypted system)? Can someone explain how to fix this security hole? Visual ...
0
votes
0answers
25 views

monitor service user account activity

I've a service account that has a full root access "user1 All=(ALL:ALL) NOPASSWD:ALL" . The user account is not used by a human user but it is used by an application which is running some bash and ...
0
votes
1answer
50 views

Ubuntu 18.04 LTS Spectre/Meltdown Status [duplicate]

I could not find any official Ubuntu information on that issue. If I check the official statement: https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SpectreAndMeltdown there is only information on ...
0
votes
0answers
15 views

Add Cert / “Security Exception” to Thunderbird 60

I have to tell my Thunderbird 60 every. single. time. that I am happy with confirming the security exceptions (our corporation cert, that is), both for IMAP receiving and SMTP sending. After that ...
2
votes
1answer
21 views

How to become the verified publisher of a Snap package

I published a Snap package in the Snap Store and I want to appear as a verified publisher because I am the developer of this app. It's open source and I manage the github repository. Thank you!
0
votes
2answers
58 views

Do I need to use canonical Livepatch? [closed]

Ubuntu says Use canonical Livepatch to increase security between restarts. I have to sign in to do this, so is it worth setting up? I'm not sure what it is; the box is unticked. I asked my I.T. ...
0
votes
1answer
42 views

How to permanently close a port?

I tried first adding a firewall rule sudo ufw deny 22 $ sudo ufw status To Action From -- ------ ---- 22 DENY ...
4
votes
2answers
411 views

What does identity file type mean in SSH debug messags?

I've been debugging a SSH connection using the following command: ssh -vT user@mysite.com And I got the following messages: debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/...
0
votes
1answer
41 views

How to get pgp's scdaemon on ubuntu 18.04?

How to get pgp's scdaemon on ubuntu 18.04? It seems that for older versions it is present, but how should I install for newer ones? PS: I'm trying to use gpg --edit-card
0
votes
0answers
17 views

Journalctl logs

I am getting plenty of such logs. My firewall seems to be blocking all of them. Oct 26 18:18:47 Host2 kernel: [UFW BLOCK] IN=eth0 OUT= MAC=00:50:56:f9:85:af:a4:f0:04:8f:a4:a9:08:00 SRC=67.58.35.280 ...
0
votes
1answer
17 views

Give scheduling rights with security.conf

I am running a C++ program which wants to enforce its own scheduling policy. It keeps giving warnings that it doesn't have the rights to, and I want to give it all the rights that it wants! I tried ...
0
votes
1answer
36 views

How to use SSL with Quassel? (Lubuntu 18.10 i386)

I executed the command in the Quassel documentation and in File > Networks > Configure Networks clicked 'Edit...' for irc.ubuntu.com:8001 and checked 'Use SSL' (with no proxy, nothing in the Advanced ...
17
votes
4answers
5k views

sudo: 3 incorrect password attempts - can root see the password in clear text?

If some user can't access some command with sudo 3 times, this should be reported to root user in access logs\errors.. Can root see these attempts (like passwords tried) in text in the logs?
0
votes
1answer
30 views

Automated Scripting [duplicate]

I was wondering if there was a way to set a chain of commands to run without having to type the in individually everytime you want to run it. That way, when I get an computer to secure I can just run ...
0
votes
1answer
33 views

Is there a way that I can know the user names of a server?

My server has been hacked a few days ago and now I decide to ban root user remote login. Is there a way that an attacker can scan my own added user name? (As far as know the answer is NO?). If so, I ...
0
votes
0answers
13 views

Updating Only Security patches on Ubuntu [duplicate]

How do i update only key security patches on ubuntu not the regular softwares command line
3
votes
2answers
478 views

Ubuntu and Spectre Meltdown

I have installed the latest BIOS on my notebook. The manufacturer of the notebook states that the BIOS update will include corrections regarding Spectre/Meltdown vulnerabilities. What microcode does ...
0
votes
0answers
23 views

How to restrict access from internet to containers ports on remote linux server?

I use docker-compose on ubuntu 18 on remote server. How, with iptables, can i block access from the internet to the docker port and only allow access to it from the localhost of this server? For ...
0
votes
0answers
16 views

Creating and retaining audit log data for 6 months before deletion

Disclaimer: I'm not an accredited nor very experienced sysadmin but have been tasked with some sysadmin responsibilities Task: Find a way to log all account management activities (e.g., account ...
16
votes
1answer
4k views

Is my server under attack? [duplicate]

Yesterday I created an Ubuntu 18.04 droplet, with a MongoDB v4.0.2 image at DigitalOcean and today I checked the /var/log/auth.log file... What I saw is this: Oct 1 16:16:25 mongodb-server-1 sshd[...
0
votes
0answers
9 views

Every second false Reverse DNS lookup query

I am having a incident within my server. My server is making a reverse dns query every second to external Host. And I am not sure how to pinned down the problem and check it why it is happening I ...
0
votes
2answers
93 views

Security risk with scripts that write to /sys/class

I was looking for a way to make my laptop's special keys work with i3-wm. I ran into this post and used the script there to create my own. This is what I came up with for the screen brightness (on my ...
0
votes
1answer
55 views

Removing W32/Parite.B virus

I scanned one of my directory with clamscan and it showed that every .exe file is infected: .../file.exe: Heuristics.W32.Parite.B FOUND .../file2.exe: Heuristics.W32.Parite.B FOUND .../file3.exe: ...
0
votes
0answers
26 views

Handbrake launcher starting problem

For some unknown reason my version of Handbrake (Snap store version 1.1.1) downloaded from the software center is not running. When I try to launch it from the root folder it got marked as untrusted. ...
0
votes
0answers
11 views

Is it necessary to apply and auto apply security updates on ubuntu 18.04 (and 14.04, 16.04)

there are ways to automatically install ubuntu security updates or to manually apply them the question for me, is it actually necessary for a productive server? as automatically applying updates ...
0
votes
0answers
26 views

Installing AIDE on Ubuntu 18.04.1

I cannot seem to get this installed. Using the following as root. apt-get install aide aideinit I do have an exceptionally large mount point and would like to exclude this. The process just seems ...
3
votes
2answers
148 views

Simplest and most scalable way to isolate ImageMagick in VM or container

For users of my web service running on Ubuntu Server 16.04 or 18.04, I’d like to integrate features from such useful programs as ImageMagick. For example, I’d like to crop their profile pictures or ...
0
votes
0answers
81 views

Desktop is visible before lock screen appears [Ubuntu 18.04]

I'm observing a somewhat strange behavior, which seems to happen in following scenario: Privacy options: Screen Lock: On, Lock screen after blank for: Screen turns off Suspend notebook and close lid ...
0
votes
0answers
32 views

What is the secure way to use DNS cache in desktop?

I want to enable DNS cache in my desktop and came across this post DNS cache on Ubuntu . Looks like in ubuntu DNS cache is disabled by default to prevent risk of dns poisoning attacks. What is the ...
0
votes
0answers
19 views

Bluetooth notification for incoming file

recently I wanted to send one file from my phone to my Ubuntu 18.04 notebook, everything went well except that the PC didn't ask me if I wanted to recieve the file, it just began recieving. What if ...
10
votes
2answers
437 views

Is quoting filenames enough security for running `xargs sudo rm -rf`?

I wrote a script that deletes all except the last two files in a folder: #!/bin/bash ls -1 --quoting-style=shell-always /path/to/some/folder \ | head -n -2 \ | xargs printf -- "'/path/to/some/...
4
votes
1answer
52 views

How to install an isolated or sandboxed debian package?

Suppose there exists a particular debian package in the Ubuntu repositories, which upon installation pulls the actual software from an external repository such as sourceforge. The software itself ...
0
votes
0answers
30 views

Protecting the File System with File Encryption

Short Synopsis of The Issue My current PC is insecure. An attacker can peek in to both my L1 cache and RAM to recover credentials from websites and scripts. I would like to encrypt my bash scripts ...
0
votes
1answer
246 views

How to configure a U2F key(such as a YubiKey) for system wide 2-Factor Authentication?

The official Yubico guide only covers enabling it for GDM login, how can I enable it for all logins including TTY, ssh, sudo, etc?
1
vote
2answers
482 views

Some supisious software making request to nmcheck.gnome.org

Since last few days my system popup a Ubuntu default web-browser and make request to nmcheck.gnome.org website and immediately shut off after this issue I can not run system update also, I am php ...
3
votes
1answer
40 views

clear terminal critical outputs

I have Ubuntu 18.04 on my win10, and I usually create my password with this line of code: echo -n "<some text generated by hand from the site's domains>" | sha256sum |cut -c-20 But today I ...
3
votes
1answer
239 views

Will Ubuntu enable RANDOM_TRUST_CPU in the kernel and what would be the effect?

According to this The Register article from 2018-08-28 and other articles, the Linux kernel version 4.19 will have a compilation flag named RANDOM_TRUST_CPU. Here's also a link to a mailing list entry ...
0
votes
0answers
24 views

security/firewalling

I moved on ubuntu (mint tara) recently for security reasons, after I wiped my windows for the 3rd time… I’ve been cyber harrassed for the past few months, especially by a hacker who lives nearby (...
0
votes
0answers
28 views

Need to block ctrl +H (Hidden file assess) and need to do it in command line [duplicate]

I need to block Ctrl+H because that shortcut can use to see hidden files to the user. My primary goal is when any standard user press Ctrl+H then system not show hidden files to standard user. And I ...
0
votes
1answer
21 views

Ubuntu 14.04.5 Audit mv Command

So when I run strace on mv, it shows that it calls rename. I'm not getting audit events for 'rename' system call. I think I know why and would like some help figuring out a solution. I have a bunch ...
0
votes
1answer
487 views

How to setup fingerprint login on dell inspiron 5370

I have a dell inspiron 5370 laptop. But I don't know how to setup fingerprint login on my Ubuntu Desktop 18.04 laptop! Please guide how to setup :)
1
vote
1answer
123 views

Is my Vino server being attacked?

I installed vino on LUbuntu 18.04, and configured and started my vino server according to https://askubuntu.com/a/530196/1471 without understanding what the commands mean: $ export DISPLAY=:0 $ ...
1
vote
1answer
45 views

Disable user intervention until password entered (not logout)

I'm looking for an option to turn user input off (so to say enable read-only mode) leaving the same picture on screen without logging out from the system, but requiring password to be entered to ...
4
votes
1answer
742 views

Protecting sensitive data when giving the laptop to a technician [duplicate]

Suppose that my laptop does not boot and I have to give it to a technician for repair. This gives the technician access to my hard-drive and all the material in it. I can take out or encrypt the hard-...
0
votes
1answer
42 views

Will it be safe to use python 2.7 on Ubuntu 18.04 after python 2 EOL?

Ubuntu 18.04 will still be supported after 2020, yet python 2.7 will reach its end of life. If a CVE or a bug raises for python 2.7 after 2020, will the Ubuntu package get an official fix (through APT)...
0
votes
1answer
123 views

Where should I put the Apache headers?

I have an 18.04 Ubuntu server with a Drupal 8 site that is certified by Let's Encrypt. # sudo certbot --apache -d mydomaine.com -d www.mydomaine.com --rsa-key-size 4096 # sudo nano /etc/apache2/...
0
votes
0answers
107 views

Ubuntu desktop, wildcard nofile not working

I've tried setting the file limit to 32000 on ubuntu desktop for normal users by adding the following lines: * soft nofile 32000 * hard nofile 32000 To: /etc/security/limits.conf But, even after ...
0
votes
0answers
24 views

How do I force users to use strong password ? (Ubuntu 18.04 Server) [duplicate]

I'm using Ubuntu 18.04 Server. How do I force users to use strong password ? I already set SSH and remove root login.
0
votes
1answer
50 views

How to find a lost laptop with Ubuntu installed?

Is there a way for me to track may lost laptop when there's no tracking tool (like prey) installed on it? I tried to check the activity in my email but there's no trace. Thanks in advance.
0
votes
1answer
185 views

Cannot encrypt Ubuntu installation in dual boot

I’m trying to install Ubuntu 18.04.1 LTS on a new laptop alongside Windows 10, however, I want to encrypt the data. In this version if I select “erase everything” It makes that option available, ...