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 ...
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6answers
11k views

Can RAM retain data after removal?

Is it possible for RAM to retain any data after power is removed? I don't mean within a few minutes such as cold boot Attacks but rather 24 hours plus. Working with classified systems the policy ...
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4answers
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Old OS memory space protection - was it really that bad?

In his book Security Engineering, Anderson really focuses on how in the 90s and early 2000s programs would need to access memory that wasn't their own, and programmers programmed with the assumption ...
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5answers
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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 ...
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5answers
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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?
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4answers
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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, ...
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6answers
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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 ...
15
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2answers
1k 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, ...
14
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6answers
7k 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 / ...
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5answers
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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 ...
12
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2answers
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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 ...
11
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3answers
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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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1answer
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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 position-...
10
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2answers
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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 ...
10
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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 ?
10
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1answer
159 views

Are there any architectures currently out there that use hardware-enforced process isolation? What would it take to add that to x86?

First-time asker/commenter, long-time reader. As someone who's currently doing a lot of thinking & writing about measures that might foundationally improve computer security (ie., involving not ...
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 ...
10
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1answer
4k 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 ...
10
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2answers
367 views

How to know whether a RAM module is vulnerable to rowhammer before buying?

I'd like to know (or at least perform some reasonable guess) if a RAM is vulnerable to rowhammer attack. I haven't found any list of vulnerable or secure RAM modules. I've seen some general rules (...
9
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4answers
825 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 ...
9
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1answer
2k views

iPhone 5/6 RAM security

I'm interested in how the RAM can be exploited in iPhone 5+, iOS 8+. I've previously discussed general iPhone encryption and from the response it reads: There are many exploits over the years ...
9
votes
2answers
357 views

Do I need to use the cipher command with a newer SSD to erase files?

I've used Eraser in the past, and recently became aware of the cipher command in Windows 8. Specifically, with the /w flag: /w removes data from portions of the volume it can access and have not ...
8
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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 ...
8
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1answer
422 views

Is exposing website performance data a security risk?

I am currently adding a subsite to some websites that allows me to monitor performance data live as the server software perceives it. The data is mostly stuff like amount of memory used, memory ...
8
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3answers
487 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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5answers
161 views

Can secrets be made safe in memory?

Say, I am running an application on a cloud server such as AWS. Suppose I supply a key at run-time (so its not stored anywhere alongside/inside code), is there a way to secure this key in memory? So ...
8
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1answer
772 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. ...
8
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3answers
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Memory dumping Android

I need to evaluate the security of a cryptographic library. In particular I am targeting a part of the library where I believe the private key is exposed for a limited time in the RAM. Any ideas or ...
8
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1answer
161 views

How long would a computer have to be off to be resistant to a cold boot attack?

I understand that the longer a computer is off, the more resistant it is to a cold boot attack. I also understand that an AES key can be reconstructed from a redundant round key schedule even after a ...
7
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3answers
478 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?
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2answers
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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 ...
7
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1answer
229 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 ...
7
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2answers
166 views

Do password managers leak information with swap memory?

The post How to find passwords in memory (password managers) concluded, that passwords are visible in plaintext if you login to a website. Password managers tend to store the passwords encrypted in ...
7
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1answer
131 views

Methods of cold boot attacks in the wild

As far as I know, there are two methods for performing cold boot attacks: Reboot the system into an alternate operating system or BIOS with a minimal memory footprint which automatically exports ...
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6answers
1k 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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2answers
2k 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
4k 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 ...
6
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1answer
308 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 ...
6
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1answer
458 views

Are encryption keys wiped from RAM before hibernate, or how to do it (Luks and Truecrypt)

Using Linux, I have system and swap/hibernation partitions encrypted with LUKS, and data partitions encrypted with Truecrypt, and I am wondering when I put my laptop to hibernation if the encryption ...
5
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3answers
224 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 ...
5
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3answers
290 views

Can someone read a iOS class variable from outside the app?

a class variable like this: @property (strong, nonatomic) NSString *privateValue; Can someone read the value of that variable while it´s in memory? I can´t find anything about this on the apple ...
5
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2answers
162 views

Possible way to extract sudo password from running system via the clipboard

I use to copy and paste my sudo password from a KeePass file so I guess the plain text user password will be saved in RAM at some point when I use it, for example, to accept an update. Is that right? ...
5
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3answers
170 views

How to mitigate heartbleed like attacks prior to zero day

Whenever sensitive data such as a password is used on a server it resides in memory for a short time. Given that security flaws like heartbleed exist which have the ability to 'bleed' memory for their ...
5
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2answers
259 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
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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
3k 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 ...
5
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1answer
2k 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
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Was TRESOR integrated in the Linux kernel?

If a computer is switched off, the data can stay in RAM memory for a while; decaying over about 5 minutes. This can be made longer by cooling the chips: https://citp.princeton.edu/research/memory/...
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2answers
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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 ...
5
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1answer
33 views

Ring 1 and Ring 2 Memory Protection Architecture

I have heard that Ring 1 and Ring 2 memory protections are basically no-longer used within modern systems. However, when I checked into things, all I found was that these rings are somehow associated ...