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58

We always hear... Do we? I don't. Installing some untrusted program as a normal user is a bad idea with Linux the same it is with Windows or Mac: this program has access to all your data and can delete these data, send these data to somebody else etc. Moreover it can make screenshots, control other applications running on the same X windows screen (even if ...


36

Well this answer ended up fairly long, but sandboxing is a huge topic. At its most basic, sandboxing is a technique to minimize the effect a program will have on the rest of the systems in the case of malice or malfunction. This can be for testing or for enhancing the security of a system. The reason one might want to use a sandbox also varies, and in some ...


33

tl;dr: container solutions do not and never will do guarantee to provide complete isolation, use virtualization instead if you require this. Bottom up and top down approaches Docker (and the same applies to similar container solutions) does not guarantee complete isolation and should not be confused with virtualization. Isolation of containers is achieved ...


33

In short: yes, being on a low-privilege account helps protect you against malware, but does not make you immune. Like any security measure, no single thing is going to keep you 100% safe. TL;DR: Running on a low-privilege account (aka "principle of least privilege") should be part of a balanced breakfast which also includes good firewall configurations; ...


24

I was curious of this myself once, and wrote a small program under linux that malloc'ed all available memory and dumped it to disk. It turned out that it was all zeroed out before it was handed to my application. Later, I also checked the kernel code, and could confirm it was the kernel who did it. -- I think it makes perfectly sense that it is the OS ...


23

In Linux, processes is able to read another process memory when any of the following conditions applies: The process had root permission or it can read /proc/$PID/mem or /dev/mem, by default /proc/$PID/mem and /dev/mem are only accessible by root Parent process can fork()/clone() in such a way that allows it to read some or all memory of its child processes ...


17

Yes, it can be done as (theoretically) every "computing device" is computationally equivalent to every other computing device. Look up the Church-Turing thesis if you are interested. However your question is grounded in practice and in this case the answer is "yes, but it would cost too much". Effort in virtualisation today aims at speeding up the virtual ...


13

Why aren't applications sandboxed by default on Windows? I don't know, but I'm guessing it is a mixture of the following reasons: Sandboxing breaks many applications, in complex and subtle ways. Users will be unhappy if Windows turns on a new feature by default that breaks even one of their applications. It is very, very difficult to design an on-by-...


12

It seems to me you're discussing two things: sandboxing on the desktop and then strategies for user content access in sandboxed applications. Sandboxing There are many sandboxing models out there, including the ones used by OSes: Windows 8 WinRT Store Apps OS X Sandboxed Store Apps iOS Apps Android Apps Some apps are shipped sandboxed, for instance ...


12

Whilst the answer from @jens-erat has the correct high-level point that virtualization provides superior isolation to containerization solutions like docker, it is not a black and white setup. On the one hand there have been a number of guest --> host breakouts in virtualization technology (for example the "Venom" vulnerability in virtual floppy device ...


11

Codepad explains how they provide security on their about page: codepad.org is an online compiler/interpreter. [...] The strategy is to run everything under ptrace, with many system calls disallowed or ignored. Compilers and final executables are both executed in a chroot jail, with strict resource limits. [...] Rather than rely on just the chroot ...


10

You said you are going to load the third-party content in an iframe, but will the third-party content be hosted from the same domain as your main content, or will it be served from a separate domain? If the third-party content is hosted on the same domain as your main page, then no, your approach is totally insecure. Content in an iframe has full scripting ...


10

Very common implementation is sharing sessions in the same process. E.g: you are logged into your bank account in tab A. When you copy the URL and paste it in the tab B (of the same browser-window), then: you are still logged in. The situation should be different when you start another process of your browser and paste the URL into another browser-window. ...


10

Each version of Android is incrementally stronger on this front than the previous, and Lolipop certainly pushes application sandboxing a step further than Kitkat, particularly with respect to inter-app isolation. Third-party "firewall" apps on Android are probably a bit over-hyped, and the level of protection they can offer without rooting is in my opinion ...


9

The attack you describe doesn't work on Windows. Starving the page-zeroing thread doesn't prevent zeroing, it only delays it. The existence of the page-zeroing background task is a performance optimization. Basically, a naive memory manager with a privacy guarantee works like this: reserve a page from the freed list zero it make it available to ...


9

This is a horrible case of Security Theater Security Theater is the practice or belief of something that looks like it improves security, but in reality does little/harm to it. This false belief has been around as long as the following rumor Linux has no viruses because of it's permission system That's almost as good as saying I don't have a virus ...


8

Honestly some people need a wake up call before they take responsibility for their mistakes. Give the company a set time, like one month from today to release a patch. If they do not comply post information about the vulnerability on the Full Disclosure Mailinglist. By not making this information public then you are risking that organized crime will ...


8

The term "sandbox" is wide, generic, and often misused and misunderstood. Let's consider a type of sandbox, a virtual machine running under control of an hypervisor. The guest system is nominally isolated and cannot "see" the host system. However, this is relative to the implementation of the hypervisor, which is a combination of software and hardware, both ...


8

There are some security benefits to running the browser in a sandbox. If the browser gets compromised, then the sandbox can limit the damage. However, there are also serious usability implications of running your browser in a sandbox. For instance, say you want to download a document off the web and save it somewhere for later use. Nope, sorry, no can do:...


8

From their product page, we can infer a lot about how their system works. Here are the key points: Can be used with Windows XP and Windows 7 Comes with: VirtualBox 4.0.16, hardened Linux Debian 6 and SELinux and Firefox Browser execution takes place in separated virtual machine with own operating system Downloaded files are first scanned and then ...


8

Start with this guide -- https://github.com/hfiref0x/VBoxHardenedLoader -- it's incredibly up-to date in terms of making a VirtualBox guest VM more-difficult to detect, including techniques valid in 2017. This will definitely make your automated malware analysis initiatives and goals easier to achieve. Consider tracing and debugging outside of the guest VM ...


7

I'm far from being a PHP expert, so my comments are more general rather than specific. Probably not entirely, but it depends. I don't think that any whitelist/blacklist approach can ever be 100% accurate. There will always be a case of false positives or false negatives. So you're always balancing between hits (of a script being able to still penetrate ...


7

Malware analysis should be done in a VM preferably disconnected from the Internet. This is mainly to protect your system, and stop it from spreading (if the malware has that capability). You can also use snapshots, or sometimes you can setup a VM to never keep state. VirtualBox is free and will do the job. VMWare Player is also free, but limited. Doesn'...


7

Actually lorenzo's answer does not quite cut it. The Church-Turing thesis only provides us with a model of computing, it can't tell us anything about virtualization because it is not concerned with other aspects of a machine. But there is theoretical analysis for the ability of a machine to be virtualized by Popek et al: http://cs.nyu.edu/courses/fall14/...


7

Yes, it is possible to read iOS class variables from outside of an app. Depending on your perspective and proclivity towards jailed or jailbroken devices, you may find a few ways to read them at runtime or in-memory. Via runtime, on a jailbroken device, a tool such as NCC Group Introspy is a developer-friendly tool that doesn't require any formal reverse ...


7

Yes there are security risks, especially if you allow arbitrary formats. FFmpeg supports a huge variety of formats, both popular and obscure, for video, audio, and images. Any vulnerability in decoders for any of the numerous formats could be exploited to gain arbitrary code execution. This becomes even more likely given the fact that FFmpeg is written in C, ...


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