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.

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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 ...
15
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4answers
6k 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, ...
15
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6answers
2k 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 ...
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4answers
3k 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 ...
13
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6answers
4k 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 / ...
12
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2answers
576 views

What are the security implications of “Row Hammer” attack?

I just found out about the Row Hammer attack. Based on the description, this sounds extremely dangerous, but I wonder what percentage of devices are actually affected by these. Are there any ways to ...
12
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2answers
949 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, ...
11
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3answers
3k views

Why is it dangerous when an attacker can control the `n` parameter to `memcpy()`?

I was reading a paper and saw this piece of code has an information leakage vulnerability. It was saying the following code will Leak memory layout information to the attackers Could somebody please ...
11
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5answers
3k 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
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1answer
852 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 ...
10
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1answer
2k 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
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4answers
2k 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 ?
9
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1answer
3k 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 ...
8
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4answers
661 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
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3answers
231 views

How private is RAM from other users on a VPS?

Can I safely assume that my RAM never can be accessed by another user on e.g. EC2 or Digital Ocean, if we suppose that I trust my provider and we don't consider possible bugs (such as Heartbleed) in ...
8
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1answer
147 views

Is it unwise to use Redis to store PII, private keys, and other secrets?

I'm reviewing a system that is using Redis to store all client secrets, private keys, and other things. The problem is that Redis loads the entire DB into RAM Since SSL's heartbleed, Rowhammer, and ...
7
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2answers
799 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 ...
6
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6answers
967 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
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3answers
5k 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
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3answers
2k 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 ...
6
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1answer
191 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 ...
6
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2answers
1k 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 ...
6
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2answers
3k 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
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2answers
380 views

Why are buffer overflows executed in the direction they are?

I'm following The Security Tube’s video here. He overviews buffer overflows, and mentions how memory is executed from highest to lowest in the stack (at least with his implementation I assume). So we ...
5
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3answers
341 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?
5
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2answers
219 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 ...
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3answers
633 views

Why does printf() vulnerability require 4-bytes of junk data? - “Hacking: The Art of Exploitation”

I've been reading "Hacking: The Art of Exploitation 2nd Ed." and I hit a part that's not explained clearly enough for me. In the section "Writing to an Arbitrary Address" Jon Erickson creates a ...
5
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1answer
695 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: ...
5
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1answer
183 views

Is it more secure to overwrite the value char[] in a String

I am talking about the Java implementation. Is it more secure to use reflection in order to access the internal Field value of type char[] inside a java.lang.String instance and overwrite the ...
5
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1answer
313 views

What does EMET do for Windows 8.1?

I recall seeing, upon release of Windows 8 a while ago that a number of new mitigations and memory protections had been put in place but i'm unsure if these are the same protections offered by EMET. ...
5
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1answer
3k 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
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2answers
439 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
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3answers
163 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
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2answers
608 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
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4answers
5k 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
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4answers
5k 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 ...
4
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1answer
79 views

Principles of memory forensics tools

I am currently writing a thesis about digital forensics which includes a chapter about memory forensics. Besides the tools and the methods of acquiring various data with them, I am kind of desperate ...
4
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1answer
363 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 ...
4
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1answer
282 views

Does Linux kernel use DEP for kernel memory?

Does the Linux kernel use DEP internally for its kernel memory? In other words, does the Linux kernel take care to ensure that, when the kernel is executing (in kernel mode), every executable ...
4
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1answer
466 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
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5answers
530 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 ...
3
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1answer
859 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 ...
3
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2answers
577 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
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2answers
444 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 ...
3
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2answers
131 views

Crypto software: overwrite sensitive buffer

Is it common to implement crypto software in such a way that sensitive buffers are overwritten before free'ing memory? For example when they contain a private key or the plaintext message.
3
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1answer
200 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
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3answers
323 views

C++ memset() memory overflow

I am new to C++. Can any C++ expert tell me would this causing buffer overflow? Sample Code: MyObject op; memset(&op, 0, sizeof(MyObject)); On my view it is ok to be this since the limit is ...
3
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1answer
121 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
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1answer
572 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
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1answer
266 views

File Vault 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 ...