Computer memory refers to a physical device that is used to store sequences of instructions (programs) or data (program state information) on a temporary or permanent basis for use in a computer.

learn more… | top users | synonyms

257
votes
13answers
52k views

Are passwords stored in memory safe?

I just realized that, in any language, when you save a password in a variable, it is stored as plain text in the memory. I think the OS does its job and forbids processes from accessing each other's ...
13
votes
6answers
1k views

How can the impact of cold boot attacks be minimized?

Short of powering down and maintaining physical security for sufficient time, what are effective strategies for keeping keys from being disclosed by cold-boot attacks, and can anything be done without ...
12
votes
4answers
2k views

Why encrypt data in memory?

I saw that KeePass not only encrypts its password-database-file, it also can encrypt the passwords it holds in memory. This is just an example. I thinking of a new project dealing with sensitve / ...
10
votes
5answers
2k views

What is the benefit with using encrypted RAM Memory?

I sometimes hear that encryption is used for the RAM Memory, but I don't really understand why this is needed. Why is RAM Memory needed to be encrypted? and is this done by the hardware, the ...
10
votes
1answer
1k views

Effects of DDoS attacks on memory use under Linux

Can someone whose Linux system is under DDoS attacks give me exact data on the effects of the Low Orbit Ion Cannon (LOIC), the High Orbit Ion Cannon (HOIC), Slowloris, PyLoris, Hping etc. on memory ...
9
votes
2answers
1k views

environment variable accessibility in Linux

Perhaps this is a trivial question, but how accessible are environment variables in Linux between different users? e.g. if Alice executes export FAVORITE_FOOD=`cat /home/alice/fav_food.txt` Can ...
9
votes
4answers
4k views

OS with encrypted RAM?

Are there any applications, JIT frameworks or operating systems that focus on encrypted virtual memory, or perhaps virtual machines that do something similar? I know there are processors (albeit old, ...
9
votes
2answers
713 views

Protection of Keys/Passwords on Virtual Hardware (XEN, KVM, VMWare, etc.)

Is there any reasonable way to secure data on virtual hardware? What I mean by "virtual hardware" is the various hosted systems that one can rent from various online hosters, that run on top of XEN, ...
8
votes
4answers
508 views

Why don't computers check whether there are memory contents in some memory space?

Buffer overflow occurs because it writes to memory spaces that are used by, or will be used by other parts of the program. Computer programs usually write to the memorylocation that has been ...
8
votes
4answers
1k views

How does System Memory Dump work?

So there are so many pen-testing tools that perform a memory dump on the system. How exactly do they work - what exactly happens ?
8
votes
1answer
311 views

Why are some DLLs not randomized? What makes it hard to deploy full ASLR for all DLLs?

One of the challenges with deploying ASLR for everything is that, at least on Windows, some DLLs (libraries) are not compiled in a way that's compatible with ASLR. (They're not compiled as ...
8
votes
1answer
907 views

How to properly delete all data from cell phones?

Lately I've been thinking to get rid of some old smartphones; among them an Android device and a Blackberry. Not selling or recycling them is the ideal solution, however, I still would like to know ...
6
votes
6answers
757 views

Implications of securing data in RAM

Someone told me that his company is storing all application data (at least the sensitive data I guess) in RAM for security. Their application runs for long periods of time, so data stays in memory for ...
6
votes
3answers
3k views

Recover the prior contents of RAM from a turned-off PC?

I've heard that if your PC is turned off, then an attacker can recover the RAM from the last session. I find this hard to believe. How could it be done?
6
votes
3answers
1k views

SSD (Flash Memory) security when data is encrypted in place

I'm surveying current techniques on flash memory security. I've learned that the non-in-place update of flash memories prevent us from adapting the same encryption techniques that we used on hard ...
5
votes
1answer
156 views

Do 64-bit applications have any security merits over 32-bit applications?

A particular article from arstechnica.com stated this. One of these protective measures is called Address Space Layout Randomization, ASLR, and it works by moving DLLs and application memory into ...
5
votes
2answers
263 views

How can I detect (or inventory) all DLLs that don't use ASLR?

Based on this IE zero day, I'm interested in listing all DLLs in our systems that have been compiled to not work with ASLR. Ideally, I'd like to analyze a static file and not load it into memory to ...
5
votes
2answers
181 views

Why did it take so long to enforce memory permissions?

From the Wikipedia page on DEP. DEP was introduced on Linux in 2004 (kernel 2.6.8[2]), on Windows in 2004 with Windows XP Service Pack 2,[3] while Apple introduced DEP when they moved to x86 in ...
5
votes
2answers
2k views

Safely disable firewire/thunderbolt, patching up DMA exposure

I understand that Firewire 400/800 and Thunderbolt have DMA enabled, and a malicious hardware device can easily read and manipulate system memory at will. If I disable the software drivers for these ...
5
votes
1answer
2k views

Protect access to an SD card

How can I protect access to an SD card, so that only authorized users can read or modify the content of the SD card. Currently everybody who has physical access to the SD card can read or modify ...
4
votes
2answers
366 views

Are there volatile memory chips which dont retain data after power off?

It was demonstrated that dram modules can retain information up to 10 min after power off in certain conditions. My question - are there memory types which will retain data 10 sec at max even if being ...
4
votes
3answers
159 views

Is there a common name for a software defect that leads to unexpected transfer of secret over the wire?

Suppose in a C++ program I use a memory region for temporarily storing an encryption key and don't overwrite that region afterwards. Then my program wants to send a data packet over the network. Due ...
4
votes
2answers
195 views

Smashing the stack if it grows upwards

As we know that on most of the processor architectures, the stack grows downwards. Hence, memory exploits involving smashing of stack and buffer overflow and their explanation make sense. Just ...
4
votes
4answers
3k views

How to make / dump contents of memory for forensics analysis?

I work as a Information Security analyst and was recently tasked to look into Incident response + computer forensics related topics. For starters, I am experimenting on my PC which is running Windows ...
4
votes
1answer
197 views

What attacks does a W^X policy prevent against?

Write xor Execute (W^X) is a policy that a block (page) of memory cannot be marked as both writeable and executable at the same time. What attacks does W^X prevent, with and without the following: ...
4
votes
2answers
686 views

Memory Dumping - Cause for concern in Virtualization?

Recently, I started exploring threats to Virtual machines in general. The first question that popped into my head was whether a host machine can dump its entire memory onto a file, and inspect the ...
4
votes
1answer
346 views

How dangerous is a virus introduced to a malicious website in chrome?

I am using Google's Chrome browser under Linux (Ubuntu) 64 bit for web browsing. If I a virus uses for example a leak in the flash player, the virus will get the privileges of the user who started ...
3
votes
3answers
275 views

An OS that does not trust its RAM?

I wonder if it is possible to write a kernel that would keep all of its RAM encrypted, storing the key in the CPU cache, so that the machine would be resistant to cold-boot attacks?
3
votes
2answers
134 views

Does a flatbed scanner remember any of its previous scans?

I'm about to get rid of an older scanner and I want to make sure that no one is able to acquire any sensitive information that was scanned previously with the machine. I assume it does have some kind ...
3
votes
1answer
163 views

how does a return to system allow an attacker to evade a non-executable stack?

I am learning about return to system call attacks for a security class. I understand that in this kind of attack, attackers replace the standard return value for a stack frame with the address of a ...
3
votes
1answer
253 views

A simple example for showing the use of Data Execution Prevention (DEP) security feature

I am finding it really hard to figure out why we need a DEP! Microsoft states this about DEP: The primary benefit of DEP is to help prevent code execution from data pages. Typically, code ...
3
votes
1answer
103 views

How can one gain additional privileges from being able to read kernel memory?

Given the ability to read (but not write) arbitrary kernel memory as an unprivileged user, what approaches might one take to gain additional privileges on the system? Ignoring the 'trivial' method of ...
3
votes
1answer
458 views

Two questions about learning Linux exploit development fundamentals

getting ready to delve into the technical world of vulnerability assessment, and I have two questions about where to find certain information. First, I plan on reading "Understanding the Linux ...
3
votes
1answer
76 views

Exploiting memory corruption issues using a DLL file

I was listening to a talk on Return Oriented Exploitation from the Black Hat 2010 conference. The speaker mentioned something about using the DLLs to exploit some of the memory corruption issues. I ...
3
votes
3answers
135 views

Protecting against Firewire DMA vulnerabilities in Linux

I know there have been questions on this in the past but they all seem quite outdated, or not that specifically relevant. I need to use a 1394(Firewire) connection, however am concerned with possible ...
2
votes
5answers
499 views

What should one do when he/she wants to protect him/her home--computer--?

As you know, deleting a file by pressing shift-delete or by using the Trash doesn't mean that the file is unrecoverable. It's data persists on your computer. In day to day life, adversaries use ...
2
votes
2answers
235 views

Can unencrypted keys & logins be kept out of program memory?

No matter what technique is used to store encryption keys & logins, it seems that all roads lead back to program memory (as far as I know), as an unencrypted version of the keys & logins will ...
2
votes
3answers
185 views

PGP on hibernation files?

I was afraid reading this: This $299 tool is reportedly capable of decrypting BitLocker, PGP, and TrueCrypt disks in real-time. It seems to me that PGP and other sensible tools have to lock memory to ...
2
votes
3answers
198 views

Resources to learn about memory allocation & security

Are there any good online resources to pick up knowledge about how memory allocations affect security? Its a new area for me, and any pointers on where to get started would be appreciated.
2
votes
1answer
125 views

US Department of Labor Watering Hole Attack

So I read this article about how the US Department of Labor's website was compromised and users were redirect to a site that installed malware: ...
2
votes
4answers
3k views

Detecting or preventing process memory injections on Windows (anti-hack)

Standard hacking case. Hack injects into a started game process and writes over process memory using WriteProcessMemory call. The situation is like this: we are hosting a game server clients join ...
2
votes
1answer
109 views

Is Enabling DEP (Data Execution Prevention) For All Programs Worth the Risks?

Data Execution Prevention in Windows supposedly is a line of defense against malicious code by "by monitoring your programs to make sure that they use computer memory safely". However, I also know ...
2
votes
2answers
318 views

Possible trojan/virus in memory?

I've extracted objects (JPEGs) from processes` memory dumps (obtained with memdump command from volatility framework) and got strange results after searching the memory pages of the main thread of ...
2
votes
1answer
169 views

Chrome: Finding vulnerabilities using AddressSanitizer

I'm reading about AddressSanitizer, a tool that can be used to find memory bugs for Chrome (and other C/C++ software). I'm a little curious about what the process of using the tool involves: 1) Is it ...
2
votes
1answer
83 views

File Fault 1 password from memory dump

I have a osx 10.9 machine with a File Vault1 encrypted user partition. I would like to remove the encryption, but I don't remember the "master key" which is the only way to remove encryption ...
1
vote
1answer
42 views

Does having non-ECC SDRAM affect security of the system?

If I don't have SECDED ECC DRAM, is it possible or realistic that a bit could flip around sshd, and grant a lucky lurker access to my system without requiring a valid password?
1
vote
1answer
84 views

Is it safe to do full disc encryption without ECC DRAM?

Our institution requires disc encryption on laptops, but I'm uneasy about using full disc encryption without SECDED ECC DRAM. Is it safe to use full disc encryption on laptops with unreliable memory? ...
1
vote
1answer
96 views

Bounds checking using Intel's MPX

Intel has recently added new instructions to their instruction set to support bounds checking. Intel calls them the Memory Protection Extensions (MPX), and they are described in Chapter 9 of this ...
1
vote
2answers
420 views

Linux Memory Protection from buffer overflow

I am practicing Linux buffer overflow exploitation. when trying to exploit a vulnerability in crossfire, everything works well and I get the shellcode placed in the right place, and the program flow ...
1
vote
0answers
60 views

How secure is a Python Pyro daemon for storing a password?

I am using the Pyro package to create a daemon which will, upon startup, prompt for a password, and then the daemon will store that password as long as it is running. Other scripts will then make a ...