Firefox is a Web browser that is smaller, faster, and in some ways more secure than the Netscape browser from which much of its code was derived.

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64
votes
13answers
9k views

Should I allow browsers to remember my passwords and synchronize them?

I wonder, how wise is it to allow Chrome and Firefox to a) remember the passwords b) synchronize them? My gut tells me that if it's not man in the middle who can intercept them, but Google and Mozilla ...
36
votes
4answers
4k views

Avast AV could read Firefox saved passwords

My friend uses Firefox's built-in password manager feature to save passwords for sites. Later, after installing Avast Free Antivirus there was a feature called Passwords on the Avast UI. When accessed ...
34
votes
3answers
8k views

Is Ghostery safe to use?

I've heard about Ghostery, a browser extension/plugin that blocks web trackers. But according to this link it sells our data. Are add-ons and plugins open source in Firefox? Is there another ...
27
votes
3answers
6k views

Firebug appears to be decrypting SSL traffic: is it the correct behaviour?

In my company we were writing a small web application which would be hosted and tested under HSTS protocol. One of my tester complained that the username and password can be seen in cleartext so it ...
22
votes
7answers
2k views

How trustworthy is Firefox? [closed]

I looked at different password managers, to swap my user-generated, more or less predictable passwords for automatically generated, secure passwords. I stumbled upon KeePass and FeeFox (for Firefox ...
22
votes
1answer
1k views

How does Firefox encrypt passwords without selecting Master Password?

I know that the file logins.json contains all my encrypted passwords in Firefox browser. How does Firefox encrypt these passwords if I don't use the 'Master Password' option? Does this mean key3.db ...
21
votes
3answers
1k views

Are official browser add-ons really safe?

Almost any browser addon/extension that I install on my Chrome or Firefox (be it Firebug, RESTClient, ...) warns me, saying: It [the add-on] can: Access your data on all website Access ...
16
votes
3answers
2k views

What security risks does Firefox 19's built-in PDF reader (pdf.js) bring?

Firefox 19 ships with pdf.js as the default PDF reader. One of the main stated goals is to reduce the exposure of users to the often vulnerable Adobe PDF reader/plugin. So what new risks does pdf.js ...
16
votes
4answers
1k views

Firefox pre-downloading

I've found out that if you download a file with Firefox, a similar window as this one pops up (in dutch in my case): ("Bestand opslaan" = "Save file") However, the file is already being ...
14
votes
2answers
30k views

How do some sites detect AdBlock Plus? [closed]

For example this one disables function if AdBlock plus is detected, and it works. Is there a way to circumvent this?
14
votes
3answers
1k views

How secure is “Firefox Hello”?

The new "Firefox Hello" feature promises easy and safe video conversation. It is not nescessary to create an account, you simply share a link with your partner to start the conversation. The ...
14
votes
2answers
1k views

Can a Firefox add-on or plug-in access the user's websites' saved passwords in decrypted mode?

Going deeper into the previous question on Firefox plugins and add-ons malware risks: Could a Firefox add-on potentially decode and capture the encrypted websites' passwords saved in the browser?
12
votes
2answers
626 views

What should I look for when auditing a Firefox extension / plugin?

I've been asked to do a security audit on a Firefox add-on developed by a third party. I am a web developer with a reasonable grasp of JavaScript but am not a browser security expert. What kinds of ...
12
votes
2answers
1k views

Any tool for scanning vulnerabilities in browser extensions?

I am scanning browser extensions of Chrome and Firefox for vulnerabilities. Is there any tool which would help me do this?
11
votes
2answers
1k views

How safe is it to use developer's version of the browsers [closed]

I have heard that the developer versions of browsers (chrome and firefox) are less secure than stable versions of them. Is it true? Is there any sense in using developer editions of browsers for ...
11
votes
2answers
3k views

Is “Fingerprint Check” enough to verify HTTPS certificates?

So I'm at place A, see this sign: and I'm writing the fingerprints to a piece of paper (this website is just an example): Ok. Then, I go to place B (other country, etc.) then I check this ...
11
votes
3answers
7k views

Is Firefox Password Manager less secure than LastPass?

After installing the LastPass password manager, I am presented with a login dialog including the option to "Disable Insecure Firefox Password Manager". (This option appears as long as the Firefox ...
10
votes
3answers
384 views

Do I have to harden IE if I'm only using Firefox?

Assume a Windows 7 system (probably whatever home version comes with the machine), with the latest OS patches, latest IE and latest Firefox. Also assume that the user uses only Firefox for browsing, ...
10
votes
2answers
2k views

How to improve the security and privacy of Firefox

What would be a sensible approach to enhance the security and privacy of Firefox? I did not find a question about this and I feel that some guidelines for casual web users would be handy. Currently ...
10
votes
1answer
208 views

Firefox trying to connect to other computers on the LAN

While running Wireshark trying to troubleshoot some other issues, I noticed several SYN connections to ports 80 and 443 on the workstation I was using. The packets were dropped. These were coming from ...
8
votes
1answer
36k views

Firefox:Secure connection failed(Error code:ssl_error_weak_server_ephemeral_dh_key)

A screenshot of the problem: Browser: Firefox 39.0 Is this a problem with my browser? How can I solve this?
8
votes
3answers
635 views

Why do Firefox and Chrome “leak” critical security information out of the browser and how can I stop it?

In studying SSL / TLS handshakes and encryption, I found a method that describes how to export the SSL / TLS session keys from Firefox to an user or environmental variable outside the browser, and ...
8
votes
1answer
686 views

Comparison between Firefox password manager and chrome password manager

As a follow up to Is saving passwords in Chrome as safe as using LastPass if you leave it signed in?, I would like to know how firefox's password manager compares, if you have a master password and ...
7
votes
3answers
3k views

How to sandbox Iceweasel (Firefox) on Debian? [closed]

Are there any tools for sandboxing Iceweasel (Firefox) on Debian systems? I'm mostly interested in tools distributed by Debian. (An equally trustworthy source would be second best.) (I suppose that ...
7
votes
1answer
218 views

Why does Firefox claim that my connection to Google is insecure?

I keep receiving this message whenever I open any site from Google: My Firefox is up-to-date, and so my Windows 8.1. Since I don't know much about HSTS, I don't know what's going on, and obviously, ...
7
votes
1answer
180 views

Protection against clickjacking in Firefox without installing addons?

On some of my workstations I never allow Javascript in Firefox. The NoScript addon is installed on these machines, but I would like to remove it and disable Javascript via about:config instead. ...
6
votes
2answers
1k views

how to view extension privileges in firefox

In Google Chrome, I can go to chrome://extensions/ and click "permissions" to view the permissions that an installed extension has been granted. I cannot find an equivalent in Firefox. Is there such ...
6
votes
1answer
340 views

Is mega.co.nz using my Browser for cracking passwords?

recently i found on my Firefox Profil, under .../storage/.../idb/ a File named "https+++mega.co.nz", i looked inside those files, some are encrypted (couldnt read it in Notepad++), but i found 27 ...
6
votes
2answers
2k views

How Do I Troubleshoot a Browser Hijack on a Mac?

My Mac is getting weird redirects with Safari and Chrome, however not with Mozilla Firefox. Since I cannot find software to do malware removal on Apple products or any good information, I am at a loss ...
5
votes
5answers
775 views

HOWTO : Email encryption in a browser

I have read about encryption and I think it's a good idea for me to encrypt my email. I run ubuntu 12.10 and use Firefox for browsing. In my quest for learning how to use gmail/hotmail to send and ...
5
votes
1answer
235 views

Is this a security flaw in Firefox 18.0?

I had a couple of .mht files which opened in IE, a browser I never use. I renamed their extension to .HTML to run it in Firefox. When I opened the file in Firefox, Firefox created new tabs endlessly. ...
5
votes
1answer
132 views

What kind of information is exposed during a Firefox private browsing session?

I'm working with Firefox 43.0.1 on Windows 7 Pro 64 bit. I just noticed an odd behavior, and I don't think Firefox used to behave this way. I had a GMail tab open in private browsing mode, and then ...
5
votes
1answer
343 views

Why does Firefox split HTTPS request?

I am using Firefox browser version 28.0. To access https://www.yahoo.com, I put a proxy with a self-signed certificate in between and my client PC can access the HTTPS site. I then sniffed traffic in ...
5
votes
2answers
242 views

Can webpages recognize that I saved my password?

If you save your logins in Firefox, username and password are auto-filled-in in corresponding webpages as soon as you visit them (if you have more than 1 account saved, you'd have to select a username ...
5
votes
2answers
372 views

Why firefox shows some connections are not secure?

I am using internet by connecting mobile phone to my laptop using usb. From yesterday,my browser (firefox) shows for all most all website. Why this happen? How can i solve this?
5
votes
1answer
4k views

Can HSTS be disabled in Firefox?

For pentesting/VA, it is, of course, imperative to be always be able to see the HTTP site of a target, if present. HSTS conflicts with this need. Without using a proxy to address the problem (e.g. ...
5
votes
2answers
4k views

Password management in Firefox, Chrome and Safari

I just read a couple of very interesting discussions on Chrome password security strategy. Chrome’s insane password security strategy Showing stored passwords - Tim Berners-Lee The following is how ...
5
votes
1answer
1k views

How does firefox sync password recovery work?

According to Mozilla Sync-new-security-model, Firefox servers are not able to decrypt your sync data without your password. So I figured that, the browser generates a key from your password, encrypts ...
5
votes
4answers
257 views

Steps after getting hit with malware or browser exploits on Xubuntu

Well, today I was browsing the internet and I suddenly got redirected to a chinese hosted malware site and firefox started going crazy. I checked the url on virustotal with my phone and it found other ...
5
votes
2answers
301 views

How do I check if a script is safe to run?

I've been using NoScript for a couple of years now but I can't seem to figure out which scripts are safe to allow and most of the time I just temporarily allow all the scripts. Is there a way to check ...
5
votes
3answers
5k views

If I use a good Master Password in Firefox, is security improved when I Remember Passwords instead of re-type?

In the old days I would emphasize that people should not select the remember passwords option because (besides the fact you tend to forget what the browser remembers) a bad guy could could display the ...
5
votes
1answer
662 views

How make Firefox ignore X-XSS-Protection header from server?

I have two questions: 1)How can I make Firefox ignore X-XSS-Protection header? I have a website which sends X-XSS-Protection: 1 header and I want my Firefox to ignore that header, because it destroys ...
4
votes
2answers
3k views

How does Firefox securely store my SSL certificate?

I'm currently testing a free personal SSL certificate (S/MIME client / authentication) from https://www.startssl.com, which installed directly into Firefox. Now when I store backup, I have to enter a ...
4
votes
1answer
43 views

Does using creating a seprate firefox profile cause a seprate security context to protect against XSS and DNS Re-binding?

I read here that I should use separate security profiles for different sorts of things; accessing sensitive information, doing system administration vs. opening links from emails. I know that ...
4
votes
1answer
2k views

Why did firefox remove Javascript injection on address bar?

Why did firefox remove Javascript injection on address bar? Someone said it was a security issue. What security issues could there be?
4
votes
2answers
353 views

Security of Firefox extensions such as Mailvelope

I am asking these question because I am not very familiar with JavaScript or the Firefox plugin/extension system. The specific context is the Mailvelope pgp extension but the questions are general and ...
4
votes
1answer
1k views

Different SSL states as seen by Safari, Chrome and Firefox

Today, I visited some sites of the German DHL group. While Chrome and Safari complain about an invalid certificate of Firefox accepts it. Which one is right, which one is wrong? Which decision ...
4
votes
2answers
79 views

Why would a modern browser allow internal resources to be loaded from an external page

Recently someone announced that several Arris surfboard models lacked any form of authentication to perform functions such as reboot and factory reset a modem with a single http call. Read more on ...
3
votes
2answers
122 views

How is HSTS handled on subdomains?

I recently audited a website with three hosts: the main site (example.com), and two subdomains (let's call them portal.example.com, and welcome.example.com). According to the response headers, HSTS ...
3
votes
1answer
522 views

I accidentally installed an adware filled Firefox [solved]

I installed Firefox using a download site, rather than the correct site. After running and installing Firefox I noticed my Chrome had an addon called swift browser added to it by a third party. After ...