Questions tagged [security]
Security covers a wide-ranging set of topics including Users, Permissions, Authentication, Authorisation, Upgrades, Firewalling, Hardening, etc.
2,487
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How to make USBGuard ask for password before new allowing devices?
If an attacker get his hands on keyboard, he still can allow external usb device from terminal without typing password. How to password protect it?
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Ubuntu 21.04. Question about using an old app
I found a Linux app called LuckyBackup. I checked the changelog and it was last updated in 2018. Safe to use an old abandoned app like this? Or best to not use it?
I’m new to Linux.
The LuckyBackup UI ...
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Was this vulnerability CVE-2021-33909 pached by kernel 5.8.0-63-generic?
On 21.7.2021 this ZDNET article wrote about serious vulnerability CVE-2021-3390: https://www.zdnet.com/article/patch-now-linux-file-system-security-hole-dubbed-sequoia-can-take-over-systems/?ftag=TRE-...
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Why does Ubuntu recovery allow root access by default [duplicate]
Ubuntu disables password based root login by default. That seems like it results in being able to boot into recovery and drop into a root shell without needing to provide a password, from where you ...
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Ask before using webcam
How can I make it so that Ubuntu will display a notification or something like that before an app tries to access my webcam and it will ask me if i approve or disapprove it?
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dual linux system security
Sometimes I use a USB stick, with a Linux OS upon it, with my main Ubuntu OS being upon a Solid State Drive.
I'm not certain how secure this is, as I tend to recall that I
was able to access the ...
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1
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361
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Cannot login in normal mode after security update (Ubuntu 20.04) 😤
It happened again. I installed a security update (I restrain the updates to Security updates only) on Ubuntu 20.04 and, after that installation the boot stalls and login never appears. I could login ...
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What is a 'known_hosts' file and what does it contains
I have navigated to /home/some-user/.ssh/ folder and found a file named known_hosts.
What is the purpose of this file and what does it contains?
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652
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Can GTK themes and extensions access my personal files?
I would like to install third party gtk themes in my laptop running on Ubuntu 20.04. I would like to know of there's any security issues in doing so.
By security issues I meant privacy issues and ...
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557
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Ubuntu Device Control
I work on the security team and we are trying to lock down our systems. We are looking for a technical solution to lock down media burning, USB blocking etc. I found USBdeview but that only allows me ...
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481
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restricting access to Startup applications for non-root user
I have been trying to make it so that non-root users cannot access the startup applications preferences, which makes you select which apps start up on launch and change these settings. Is there a way ...
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Python3 vulnerabilities
Can anyone help me to understand difference between these two python outputs.
root@ip-192-168-20-21:~# apt install python3
Reading package lists... Done
Building dependency tree
Reading state ...
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On what occasions canonical livepatch machine-token change?
On what occasions canonical livepatch machine-token change?
Is it possible to get new livepatch machine-token without fresh installation of OS?
Is it necessary to go through https://ubuntu.com/...
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1k
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Update failure due to checksum mismatch
I am using ubuntu 18.04. When I tried to update the software using sudo apt update && sudo apt upgrade, I get a checksum mismatch error:
Get:1 http://archive.ubuntu.com/ubuntu bionic-updates/...
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File present in "recent files" of nautilus, but I was not who opened it!
Consider now it is 12:05 pm. I had finished working on a file (say 12:02 pm), I saved it and I wanted to attach it to an email, so I browsed for it, selected "recent files", and oops! The ...
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Formatting USB flash drive securely on Ubuntu
After days of searching on the internet - I really need you help.
I have fresh installation of Ubuntu 20.04. No additional software has been installed. Also no changes to the system have been made. It ...
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Uknown PHP script taking 100% of the CPU
There is unknown PHP script running in the background of my system that I can't find and that re spawns every time I kill it.
A bit of information from ps about the process.
ps -Flww -p 280378
F S UID ...
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OpenSSH showing vulnerabilities. Could it be false-positive?
I am running Ubuntu 20.04.2 LTS and am using the system as a web server. I update the system on a regular basis.
I am trying to make sure my system is as secure as possible and have started to test ...
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Questions Regarding Ubuntu Server 20.04 Setup
I am setting up a new machine with Ubuntu Server 20.04 to be used as file-/media- server hosting various Docker services. I have been using Ubuntu Server before and I am comfortable with CLI, but I ...
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Whitelist URLs in Ubuntu 18.04
I'm installing an application server on Ubuntu 18.04 and the install manual requires whitelisting a number of URLs. How to do this in a fresh installed Ubuntu 18.04?
Please whitelist the following ...
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1
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Two root in system
In Ubuntu 20.04 i have two root record when i do:
getent passwd| grep root
i got
root:x:0:0:root:/root:/bin/bash
root:x:0:0:root:/root:/bin/sh
and when I use
getent group| grep root
I got
root:x:0:
...
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How can I protect against my laptop being stolen? Can it share its location?
In case my laptop gets stolen, is it possible to use some kind of service or something that shares its location at all times? In other words, what to do against the thievery?
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Gnome Online Accounts - CVE-2013-0240 [duplicate]
I'm in a discussion with Cybersecurity Team on the company that I work. I'm trying dealing to allow again this integration in our environment.
The Cyber guys expose this CVE detail. I search on the ...
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/proc/cpuinfo security
I find that some applications want to check /proc/cpuinfo but don't have access
This is on my server running Ubuntu 20.04.2 LTS, the permissions are:
-rw-r----- 1 root root 0 May 2 14:35 /proc/...
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how can I be sure my system is update with latest security updates?
am subscribed to ubuntu-security-announce list
I receive some emails mentioning that 21.04 has some bugs like
[USN-4929-1] Bind vulnerabilities
[USN-4913-2] Underscore vulnerability
however, since I ...
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2
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Why does shim/mokmanager allow to circumvent _ALL_ protections of SecureBoot? And how to fix it?
Here is what I have done:
Generated my own SSL keys (db, KEK, PK) x (cer, key)
Removed existing signatures from kernel, GRUB, shim (and all other EFI binaries in /boot) and signed them with my own ...
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345
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How did it happen that one user can access files of another user's account on the same computer? [duplicate]
On the same computer, I have two user accounts, one for work and the other personal.
On Ubuntu 18.04 I can access, for some reason, files from one account if I am logged in in to the other (from the ...
4
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1
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How to delete/modify the recovery key from the Ubuntu 21.04 encrypted disk install?
When installing Ubuntu 21.04 with encrypted disk (filesystem: zfs) a 16 digit "recovery key" is automatically created, how do i get rid of/modify it?
I am looking to:
list installed keys
...
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164
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How to ensure that my computer/laptop has a legitimate and not tampered uefi/bios
How do I verify that a pc/laptop has a legitimate and not tampered uefi and/or bios?
Let's say I was doing somethings which potentially could be dangerous. I have inserted some unknown hard drives or ...
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Does KMail stores emails encrypted at rest?
I would like to know if someone with access to my computer can read my emails and get my email provider password.
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Prevent local admin from installing any blacklisted package on Ubuntu (Desktop)
At our company there is a need for Ubuntu clients. However there are some issues regarding security. In our case, most Ubuntu users are local admin (listed in /etc/sudoers) but we would like to ...
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How to create a secure boot enabled USB flash
I want to create a Ubuntu bootable USB flash and install my apps in that, then pass USB to any other person. they should run Ubuntu from USB flash and run my applications from it, so that nobody could ...
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ClamAV MD5 sum based whitelists (*.fp) don’t work in Ubuntu MATE 20.04.2
Trying to make ClamAV ignore several files. These are almost cryptocoin miners which I do use. Cryptocoin miners get flagged by most antivirus programs for they can be distributed as malware (using ...
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NVR Viewer for Ubuntu
I've looked around and maybe I'm not searching correctly; or no one has this specific setup. I have a Sannce DT41DC1T security camera NVR. Analog cameras plug directly into the unit. Instead of ...
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What are people using currently for virus and malware checks? [duplicate]
What are people using currently for virus and malware checks? I realize there is far less need for this with Linux than with Windows, but I still prefer wearing a seat belt just moving my car out of ...
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How can I trust what I am installing? (apt,snap,etc) [duplicate]
as you may notice, I am new to Ubuntu (actually, Lubuntu). I have a question regarding security when installing software.
When using Windows before, what most people do is to download a .exe, scan it ...
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Unable to sign in to Evernote account using Tusk - this browser or app may not be secure error
I am using Ubuntu 20.04
I have installed Tusk app using snapcraft
sudo snap install tusk
Now when I open the app after signing in it shows the error message -
This browser or app may not be secure. ...
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0
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Extended Security Maintenance (ESM) for focal fossa (20.04)
I just ran ubuntu-security-status on a 20.04 installation learnt to enable ESM to get more security updates:
4667 packages installed, of which:
1962 receive package updates with LTS until 4/2025
2694 ...
2
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0
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How to use WPA3 and protected managment frames with Ubuntu 20.10?
I have an Intel AX-210 in a Dell Latitude-7480 notebook running Ubuntu 20.10. I want to connect using Wi-Fi 6E, using WPA3 and protected management frames (both required in 6 GHz).
driver is iwlfifi /...
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Can a Third-Party App Track my IP when I Use It?
I have Ubuntu 18.04 installed and I also have some apps on it, such as Microsoft Teams. Now, I was wondering: Can such apps, that are from "third parties", so to say, track my IP when I use ...
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Putting Digital Signature on PDF in Ubuntu 20.04
Adobe Acrobat DC on windows support this feature.
While snap package adobe acrobat is partially functional on linux, as it logs incompatibility message.
So actually I am looking for signing my offer ...
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2
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Is there a patch/Upgrade for Apache CVE-2020-11984? [duplicate]
There is a critical CVE for Apache HTTP server versions 2.4.32 to 2.4.44 that allows info disclosure and possible remote code execution, so you can imagine how bad this could be on a web server if ...
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How secure are official updates by UBUNTU's Update Management?
Untill now I receive my updates on a regular basis through UBUNTU's official Update Management, as provided in the package.
Being aware of threats of malware of any kind I wonder if malificent people ...
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659
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How I can ask MySQL to use password?
How I can ask MySQL to use password for root user when MySQL starting and checking for upgrade?
localhost systemd[1]: Started MariaDB 10.3.25 database server.
localhost /etc/mysql/debian-start[1126]: ...
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installing internet facing snaps as root vs regular user (with sudo priviledges)
I plan to run a WeKan instance inside an LXD container on a vps which shall be accessible via internet.
Is there any difference from a security point of view whether I do ...
snap install wekan (as ...
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273
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What should I do if my server is under the attack?
I have a mail server on Ubuntu 20.04. Yesterday I set up UFW firewall which looks like:
root@vmi514622:~# ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing),...
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2
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217
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How to easily get all HTTPS addresses that an application connects to externally?
For those who have a firewall with highly restrictive outputs, they only need to release supposedly reliable addresses for each application, so I was wondering if there is any software or command line ...
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*Error Permission denied (publickey)* Does Windows 10 Powershell Support OpenSSH Public Keys with Ubuntu 20.04
Yes I know this a Ubuntu forum..
First off all thanks for doing what you do and helping people!
Alright so I've been trying to setup SSH keys on my Ubuntu 20.04, read stuff about it online. So I ...
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Somebody trying to access my index.php file on ubuntu apache2 server (Laravel)
One of my project someone trying to access my index.php file in laravel.
Logs:-
{
"ip":"45.155.205.108","url":"/index.php?s=/Index/\\think\\app/invokefunction&...
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Delete ca certificate not working?
I have added a root ca in my ubuntu machine by using the following commands:
mkdir /usr/local/share/ca-certificates/custom/
mv myserver.crt /usr/local/share/ca-certificates/custom/
update-ca-...