Linux Security

The Linux operating system, in all its flavors, has its own share of security flaws that allow intrusions, but there are various mechanisms by which these flaws can be removed, generally divided into two parts: authentication and access control. Authentication is responsible for ensuring that a user requesting access to the system is really the user with the account, while access control is responsible for controlling which resources each account has access to and what kind of access is permitted.

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We have a vendor who has put his linux based appliance behind a firewall. If I ssh to the system from the same subnet as the linux appliance ssh succeed - giving me a login prompt and then succeeding with authentication. If I login to the linux appliance from the Outside of the firewall the conversation succeeds apparently - I get a login prompt. But when I enter the same credentials the connection is promptly terminated. If I look at the firewall I see only the allowed SSH session and no other denies to the server.
Any idea what might be going on? What logging could be looked at on the linux appliance to give us insight as to why the ssh connection is failing in the second case? Thank you
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winscp how to save shared bookmarks shortcut

i was referring below but no complete info

https://savethehealthy.com/shortcuts-for-winscp-keyboard-shortcuts.html
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hi,

I connnected to one production inace went to the log directory where bunch of log files there.

how to continuosly monitor logs for any possible errors , exceptions.

how frequently new files created?
do i have to do vi command to open the log file

please advise
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On SLES 12.2 I do the following as root user:

mkdir -p /some/directory/ramdisk
chown -R simpleuser:users /some
chmod 777 /some/directory
chmod 777 /some/directory/ramdisk

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Then I add this to /etc/fstab:
ramfs /some/directory/ramdisk ramfs defaults 0 0

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followed by
mount /some/directory/ramdisk

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What I expect is a ramfs mounted to /some/director/ramdisk, owned by simpleuser and users, with permissions set to 777.

Surprisingly, after rebooting the machine, the owner of /some/director/ramdisk is root:root, and the permissions have changed to something more restrictive. I deem that more of a feature  than a bug, but that behaviour is really annoying in the environment I use it in.

Currently I do an explicit change of ownership and permissions prior to starting the application that uses the ramdisk (in the respective script, with sudo), but I deem that not very elegant.

Any hint what causes the changes, and how to prevent them ?
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our lab recently has a new Ubuntu (14.04.1) machine but many of software package is out of date.
I try to update it before upgrade to Ubuntu 16.04. However, there is always problems for the command "sudo apt-get update"

I have googled this problem and change "/etc/apt/sources.list" several times, but the error still exists.
I am thinking the error may come from => Could not resolve 'hcapxb01'
I have no idea about the 'hcapxb01'.  My machine has internet connection but I can't ping or nslookup the  'hcapxb01'

Experts, please help me to slove "sudo apt-get update" error. Thank you
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hi,
to learn unix and its command what are best online site, learning videos, training sites that are free available out there including some books.
please advise
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Hi,

While checking the putty logs i see all same color without much indentation

how to make different color for Errors and Exception for colors
how to achieve identation
please advise
0
hi,

i have log directory with say 40 log files in it

i have to search on "NullPoinerException" on above files and find out which file has this exception and which line

how do i grep this?

can i do these kinds of things on winscp etc some gui tools rather than putty?
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hi,

In below grep command

grep -C20 command "session" fileName


what is meaning of -  and C and 20.
 please advise
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Hi,

how to import saved ssessions  from putty to mputty.(i saved about 50 sessions with names like integration, systest, prod1 etc in putty which i want to transfer over to mputty without again typing host, port saved session nae etc)

How to point mputty to use putty and get data from putty?
please advise
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One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

CIS has hardening guides for various Windows, UNIXes and Cisco switches/routers.
There are hardening guides for Juniper as well.

Now our Audit wants a hardening guide for WAF : we use F5.

Q1:
Can anyone point me to such a hardening guide for F5 WAF?

Q2:
if there's none, any link/authoritative guide indicating it's been
sufficiently hardened (as it's an appliance customized from RHEL 5?)
will be appreciated.

Need a good justification why we don't have hardening guide in place
for F5 WAF
1
How do i register SUSE Linux to customer portal?

also how to check what security packages are available to install?

I have worked on RHEL and we use subscription manager to register with customer portal or redhat satellite.

what is the procedure for suse linux? what tool similar to redhat satellite SuSE uses?
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Hi,

When i search on below command
ps -ef|grep zyz3abc
i see all the proceses running for zyz3abc
how to seach using particular port number(1567) to filter down more granular

 i tried

ps -ef|grep zyz3abc grep 1567
did not see to work.
please advise
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Hi,

shared book marks in winscp name can i give custom names like Integration Log path, Production1 Log path etc. can you please advise

if path says crm/net/logs etc on Production1, Production2, Production 3 boxes then i cannot clearly distinguish and add as separate names. please advise
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hi,

how to copy test folder files
from below
/crm/home/systemtest/security/test
to below folder
/crm/home/XYZ3ABC/config/security/test

trying cp command but not working
is -r different from -R

please advise
do i need to go to /crm/home/XYZ3ABC/config/security/test to execute cp command or  to  /crm/home/systemtest/security/test
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Hi,

Lets say i want to copy bunch of files from

/crm/home/XYZ3ABC/opt/company/bea_domains/12/xyz3abc


to

/crm/home/XYZ3ABC2/opt/company/bea_domains/12/xyz3abc2

How to this copy paste.
can i do using winscp whose interface easy to me and more convenient to work than unix screens which according to me most non user friendly

Also once i copy files i need to edit those bunch of files from xyz3abc to xyz3abc2 etc
any way i can edit files without using vi which i am not 100% comfortable.
can i use winscp to edit or any other good open source tools apart from winscp

please advise
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I have the following RPM installed on my server.  based on the security report, its RHSA-2016:0005 missing.

rpcbind-0.2.0-12.el6.x86_64

according to RHSA-2016:0005 , i need to install

Red Hat Enterprise Linux Server (v. 6 for 64-bit x86_64)
rpcbind-0.2.0-11.el6_7-x86_64

This is my running kernel. RHEL 6 x86_64.
2.6.32-642.11.1.el6.x86_64


is it true vulnerability ? or is it false positive? please explain.
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Hi,what is difference between 755 and 777 privileges to a directory or a file in unix world.
please advise
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Hi,

I see some folders( say folder_A which contains folder_C and folder_B which contains folder_D which again contains folder_#))  has xyz as owner. I want to change owner to abc to those folders and sub folders. How can i do it. How do same thing on some files say File_A and file_B etc preoperty files.please advise
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Hi,

I have a folder called

home/system/xyz

now xyz has many sub directories  like abc , def
now abc has directories like lms, pqr etc

xyz is currently owned by me. problem is others cannot see xyz and its all subdirectories for possible issues on the server settings.
now i want to give ownership to xyz directory to ADMIN user say  crm and password say p@ssword so that all the team mates who has ADMIN crm  access can view and modify any directories and files within xyz no matter how deep they are.
how to give access to this one?
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Experts - I’d like to create a Linux/Unix read-only-root role for Auditors, InfoSec and Tech Ops, so they can examine a system without risk of breaking anything.
-      Using sudo or Centrify, we can grant the privileges to run some commands as root, e.g.  ls, cat, cksum and tail –f
-      I don’t want to allow root privileges for e.g. find, view or more/less, as they can be used to modify a system

Creating the role is easy; Making it easy to use is harder
-      `sudo cat filename |less` would work fine – the `cat` is run as root, the `less` as the unprivileged user. I can create a little script utility called something like “Auditors_less” to remove the need to remember the syntax.
-      `dzdo cat filename > ~/my_copy_of_filename` would work for the same reason, and give them a local copy to work with. Call it “Auditors_cp” or just “Acp”
(`dzdo` is the Centrify equivalent to sudo)

Replacing the functionality of `find` is the part I can’t figure out. The output of `find` gives the full path to a file. `find` also allows you to select on ownership, permissions etc., but that part could be replaced by
`dzdo ls -l |grep {pattern}`

So a scriptlet that takes a starting directory as input and produces output in the form
/path/to/file      : ls –l output of file
would be great, as grep can filter the output, e.g. for globally writeable files/directories

I’ve found similar questions on formatting `ls -lR` output on stackoverflow.com, but no usable answers – general opinion seems to be…
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1. Centos server 6.9 in AD = OK

2. Only access feathers for users of group_USER_AD, applying control via /etc/security/access.conf = OK
3. Blocked root access directly to no server. /etc/ssh/sshd_config (PermitRootLogin no) = OK

 4. To use local account, you will need to use "su -" and do not log in without server with local account = OK

----------------

I have an application that runs with a local account. How can I release the user's access to use the winscp tool and write the application's non /home? Attempts without success

1.) Add the network user's AD group within the application's local group.

2.) There are many network users AD. I can not add one by one in the local group.

How do I solve it?
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Can i able to connect SuSE linux to Redhat satellite and patch?
0
Hi,
how to transfer
site booksmarks to shared bookmarks in winscp

please advise
0
Hi,

how to teach winscp remember password. Every time entering password is pain for me. please advise
0

Linux Security

The Linux operating system, in all its flavors, has its own share of security flaws that allow intrusions, but there are various mechanisms by which these flaws can be removed, generally divided into two parts: authentication and access control. Authentication is responsible for ensuring that a user requesting access to the system is really the user with the account, while access control is responsible for controlling which resources each account has access to and what kind of access is permitted.

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Linux Security