Ljm Dullaart
  • Member for 2 years, 11 months
  • Last seen this week
Security risks of fetching user-supplied URLs
28 votes

Instead of uploading an image, the user can provide the (self-hosted) URL of an image. We store the URL instead of the image. You mean these kind of JPEGs? It is a bad idea. First of all, you will ...

View answer
Computer name naming convention for security
19 votes

The fact that there is no readily available information to support your conclusion, should give you some idea about its validity. The point is, that if your attacker is already in, he will need to do ...

View answer
Are there security reasons for prohibiting universal mac address modification?
Accepted answer
5 votes

It is difficult to answer this question, because we don't have any insights on the way of thought of those at MicroSoft. However, as you said, there are two types of MAC's: a universally-administered ...

View answer
How can I explain our system admins that AV can't protect our enterprise machines from attacks leverage on USBninja?
5 votes

It surprises me that you have to. But then, they might be unfamiliar with the USBninja. Explaining what the USBninja does should be sufficient for sysadmins. But the best way is to show them. Buy one. ...

View answer
Is Linux really not spying on us?
4 votes

It depends quite a bit on your definition of 'spying'. For example, the Ubuntu distribution as a default has "Yes send the systeminfo to Canonical", which means that Canonical collects ...

View answer
Why should password reset link be single use?
4 votes

The threat that is being mitigated by the single use is that someone else uses (or re-uses) the url to reset the password. If the url does not work, apparently someone has intercepted the mail and ...

View answer
Reason for fake academic pdf files found on sites like Google Scholar?
4 votes

The answer is in your warning: found that it is malicious. When a malevolent person creates a malicious pdf, (s)he wants as many victims as possible. So , adding a wagon-load of keywords attracts ...

View answer
Is it social engineering when you know you are being social engineered?
4 votes

Yes. If you know you are being cheated, you are still being cheated. For social engineering, this may mean that you are warned, and that the attempt will probably fail. But social engineering in ...

View answer
How are vulnerabilities like PrintNightmare CVE-2021-34527 discovered?
Accepted answer
3 votes

There are many ways that vulnerabilities are discovered. Random fuzzing is one, systematic testing is another. Sometimes something is discovered by accident ("when I print this PDF, always ...

View answer
Using an example to comprehend why “safely” erasing a drive yields better results than filling it up with meaningless data
3 votes

Well, it depends a bit on what flash drive is used. In general, flashdrives (and SSDs for that matter) use wear-leveling and over-provisioning. So, if you're using expensive, industrial grade flash ...

View answer
Making Users Prove They Have Reviewed The Information Security Policy Documents
3 votes

Getting a web-page up with authentication and detection of "scroll to the bottom" should be fairly simple. See also https://stackoverflow.com/questions/3898130/check-if-a-user-has-scrolled-...

View answer
Block HTTPS/TLS (Wo)Man in the Middle Attack
Accepted answer
3 votes

In general, it is easy to get some information about the browsing of a person. The information that is leaked is: site that you are using approximate length of the URL approximate length of the page ...

View answer
Getting real machine information from a virtual machine
Accepted answer
3 votes

Ideally, the virtual guest is not able to see anything from the host. But the world is not ideal. Here we go back to the discussion of Joanna Rutkowska. She developed a technique to determine to test ...

View answer
Another domain pointed to my server, what are the risks?
Accepted answer
3 votes

There are a number of risks, for both you and (assuming it was a mistake) the domain owner. For you, it means at least exposure. In some cases, that can mean more DDOS attacks. If the domain owner ...

View answer
ISP provider does not giving permission to change my router password
3 votes

No. It means that your ISP provider can basically control your network. Change DHCP ranges, control port forwarding etc. In a business situation, with sufficient contractual assurances, this might ...

View answer
Firewall logs with Local IP contacting local IP over the internet
3 votes

Not giving much details means that you get a global answer. 161 is SNMP. Not traps, SNMP. Anything doing an unexpected SNMP should be subject of investigation. The process may be called something ...

View answer
Is a company decrypting all SSL traffic through a Root CA GDPR compliant?
3 votes

The problem with the GDPR lies in the remark: "without even notifying this software is being installed". In that case: no it is not compliant. If you dig a little deeper, you will find that in almost ...

View answer
What to do when you simply cannot trust anyone or anything anymore?
2 votes

There is no solution. The problem is that you need to trust something to get anything done. The problem translates itself to the real world too. If you buy food in a supermarket, you trust quite a ...

View answer
What PDF file format alternative should I choose if I am looking for more security in my document files?
2 votes

There are a number of ways to divulge documents, all with their pro and cons. A simple comparison of a number of common formats is: Format Pro Con MS Word .doc ...

View answer
How to create custom exploit https requests to test a PHP framework
2 votes

For Linux systems, gnutls-cli is available. For example: gnutls-cli qnap --no-ca-verification GET index.html gets the index.html from my Qnap-NAS via port 443. You can of course easily make invalid ...

View answer
Does Password Harvesting Happen in Servers?
2 votes

You could. It is a valid concern for sites with owners that are under less scrutiny than Microsoft and Facebook. There are a number of points that make this a less likely option though. Many will be ...

View answer
Is there any proof in support of these basic security guidelines?
2 votes

This group describes itself as: Since 2018, the group has concentrated on fundraising from the tech community for candidates for public office. It claims no knowledge about IT, but it suggests that ...

View answer
Can I check the content of a suspicious file directly on the server using an editor, e.g. vim?
2 votes

If you have files that you cannot explain, then you have a security risk. It is as simple as that. If possible, take the site off-line. Then run a copy to a place where you can do forensics. If you ...

View answer
Any risks connecting to a Chinese printer?
2 votes

There are all sorts of possibilities. Yes, your printer can have a call-back mechanism, with a 5G GSM SIM. Yes, your drivers can send a copy of everything you print to the Chinese authorities via the ...

View answer
Why can't we protect the password file so that only the system can read it?
2 votes

There is no reason why you can't design an OS this way. The reason why it is not done is, that it requires a new system approach. For example: if you use a Linux or Linux derivate, there is always the ...

View answer
Real-world use of restricted shells
2 votes

No. In my experience, they are (almost) never used. There used to be an idea that, if you could restrict the shell, you could limit the user's access to the system. However, for a determined user, ...

View answer
Can not logout when the network is unreachable
2 votes

If a server has no connection with your client system, your command to log off can never reach the server. Most web services use cookies to determine who is logged in. If you need to terminate the ...

View answer
Looking for resources for interpreting my security logs
Accepted answer
2 votes

The only thing that you can do is to dive into the log and for every record see what that means and what the implications are. That is hard work. I know, and you will expand your security knowledge. ...

View answer
What are the tradeoffs between a common login site and login-per-site?
1 votes

From a security point of view, both have their own issues and both have their advantages. Both can be made more or less equally secure. If you use a login-page per service, you might want to ...

View answer
Is using VPN more secured when working remotly? Is using VPN more secure when working at the office?
1 votes

It is indeed bizarre that the company advises you to connect to the Internet using a VPN. In general, companies prefer to know who is connecting to them and the VPN break-out point serves somewhat as ...

View answer