Nmap doesn’t show physical hosts

~# nmap -sn Starting Nmap 7.80 ( https://nmap.org ) at 2020-07-02 18:11 +01 Nmap scan report for Host is up (0.00068s latency). MAC Address: 52:54:00:12:35:02 (QEMU virtual NIC) Nmap scan report for Host is up (0.00067s latency). MAC Address: 52:54:00:12:35:03 (QEMU virtual NIC) Nmap scan report for Host is up (0.00070s latency). MAC Address: 52:54:00:12:35:04 (QEMU virtual NIC) Nmap scan report for Host is up. Nmap done: 256 IP addresses (4 hosts up) scanned in 2.04 seconds 

i use a virtual machine, and Nmap shows only the virtual hosts

Is there a way to limit cookies to certain hosts in HTTP?

Using Nginx, I hope to restrict the permissible hosts for cookies. My initial intention was to employ a Content Security Policy for this purpose, but I don’t see an obvious way to do this via a CSP. Ideally I’d find something like

Restrict-Cookies-Header: hostname1.tld hostname2.tld2 

Can something like this be accomplished with HTTP headers? Thanks!

How can I scan for a specific CVE on my own hosts?

We have an application which was vulnerable to CVE-2019-18935 and a malious file was injected into a temp folder (but not executed it seems). We have now resolved the issue by updating a 3rd party Telerik library, but it occurs to me that we could/should have known about our exposure to this much earlier than this month (May 2020) so I’ve been trying to find out how I could have scanned for this vulnerabilty in advance of being exploited?

I have tried to use Kali Linux’s nmap, with the “vulners” script, but it returns several CVEs (which seem to be false positives) and don’t mention the “biggie” which is the Telerik one: https://nvd.nist.gov/vuln/detail/CVE-2019-18935

enter image description here I had updated nmap and the databases (from their original Git source) so why would it not know about (or fail to detect) CVE-2019-18935?

Is a firewall enough of a security measure for an Ubuntu server that hosts a website?

I recently got a VPS with Ubuntu on it, and I’d like to start creating a very basic website. However, I don’t know what steps I should take to secure this server.

I’m new with Ubuntu, new with security and new with creating websites (the website will probably be just HTML, CSS, Django/Python and some database).

My biggest concern is that some hacker could try to use it as a zombie and I won’t know. Or that robots could try to log in and sneak at whatever data I’ll store on that machine and I won’t know. Or who knows what else.

I found the firewall information page on the Ubuntu website, but will that be enough ?

P.S.: If it’s impossible to give an answer, I’d also appreciate a book/website recommendation for Ubuntu and security complete beginners

Should a DNS server restrict reverse lookups from external hosts?

What risks are there in allowing external clients to resolve internal IPs to their domain names? The server is used internally for clients, as well as for external clients needing to resolve a web server’s domain. Couldn’t allowing these reverse lookups allow an attacker to gather a wide array of information if the domain names contain usable information?

[ Politics ] Open Question : Do you think Abby Huntsman and Meghan McCain should stand with their View hosts and call for Trump’s impeachment?

Trump has insulted Meghan’s father so many times and yet she’s still Republican.  She has even defended some of Trump’s actions: same with Huntsman.  Her father worked for Trump as an Ambassador.