Questions tagged [exploit]

Using techniques to change the behavior of an application or application component in order to use it to ones advantage. When used it is often referred to software exploitation where an attacker can take control of an applications execution flow in order to run arbitrary code.

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Knowledge about CPU hardware

Recently, I have taken the computer organization course that explains in the logic gate level how a CPU works and etc... Up until now I have been treating the CPU as a black box that runs assembly ...
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3answers
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How exploit writers find bugs in Java Machine?

My question is about Java exploits, for example this one: https://www.us-cert.gov/ncas/alerts/TA13-010A (exploit avaiable here http://www.securityfocus.com/bid/57246/) The victimn should visit the ...
13
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1answer
26k views

Managing inputs for payload injection?

I am looking for a complete list of the ways to inject a payload in a vulnerable program in a Unix (Linux) context depending on the inputs opened by the program. I know that there are several tricks ...
12
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2answers
817 views

How are vulnerabilities (especially buffer overruns) found in the wild?

I hope this question is not OT for RE, but I'm rather curious as to how vulnerabilities are usually found. Of course I'm aware that companies are doing code audits to identify security problems but I ...
12
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1answer
4k views

Howto clone Android RSA SecurID Software Token

At the moment I try to figure out how the RSA SecurID Software Token protects itself from getting cloned to another android device. The token I imported has no device binding enabled and I already ...
11
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4answers
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Converting assembly code to c

I have the following assembly code over Linux distro: # using the .data section for write permission # instead of .text section .section .data .globl _start _start: # displaying some characters ...
11
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1answer
5k views

Understanding the most recent heap implementation under Linux

A few days ago, I was wondering how one could teach himself heap-based overflow exploitation. So I searched through documentation, subsequently practicing what I read in order to have a better ...
8
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1answer
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Understanding this Buffer Overflow exploitation

some days ago I took this piece of code from opensecuritytraining.info to test a buffer overflow exploitation: #include <stdio.h> char *secret = "pepito"; void go_shell(){ char *shell = "/...
8
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2answers
367 views

Decompiling return-oriented programs

How are return-oriented programs decompiled/reverse engineered ? Any pointers to any papers or reports would be appreciated.
8
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1answer
15k views

Illegal Instruction exploiting sample Buffer Overflow code

Some days ago I coded a simple code to test a buffer overflow exploitation on x86 system. In order to keep it simple I disabled ASLR and NX so there are no protection that could cause weird behaviours....
7
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3answers
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buffer overflow exploits - Why is the shellcode put before the return address

The code I'm referring to is found here: Link to code I read that the buffer overflow exploit uses a buffer that looks something like this: | NOP SLED | SHELLCODE | REPEATED RETURN ADDRESS | From ...
7
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2answers
325 views

Lego NXT Exploitation and Vulnerabilities?

First, I wasn't sure if I should post this on the Lego Stack Exchange site or here, and I decided this site had more to do with the question (I hope I don't get bad rep for this). OK, my friends and I ...
6
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2answers
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How does Windows SafeSEH mechanism work?

How does Windows SafeSEH mechanism work? I understand how the overwriting SEH exploitation technique works. I do not quite understand how the SafeSEH mechanism works preventing this technique from ...
6
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3answers
2k views

Fuzzing Adobe Reader - Exploit Development

I have been fuzzing Adobe Reader lately. I found couple of bugs. One of the major issues that I'm facing are listed below. How to identify the root cause of the issue? I mean, the PoC has a large ...
6
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1answer
3k views

ROP exploitation in x86_64 linux

I am working on return oriented programming exploitation on a x86_64 Linux. However, my research leads to impossibility of ROP exploitation in 64-bit Linux machine because all of code segments are ...
6
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1answer
379 views

Returning to usermode shellcode from windows kernel (Win10)

I have written a kernel exploit (for the latest Win10 64bit) that executes (or returns to from the kernel) token stealing shellcode, which is placed in the VirtulAlloc'ed memory in the userland. The ...
5
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2answers
269 views

Embedding URL call into an image / movie

Is there a way to embed a URL call in the raw data of an image or movie file, such that when the image or movie is opened, it makes a call to a webserver? I want to be able to obtain someone's ...
5
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1answer
3k views

Writing an exploit for sample-application

I understand the principles of exploiting a classical stack-based buffer-overflow, and now I want to practice it. Therefore I wrote the following test-application: #include <stdio.h> #include &...
5
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1answer
341 views

Do you have tips analyzing reported PoC(exploit) files?

My daily job is analyzing reported proof of concept files that exploits document viewers. People who report vulnerabilities in document viewers just give me the PoC and vulnerable version number. They ...
4
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1answer
859 views

Heap Chunk Structure Does Not Contain Previous Section Info

I'm reading Shellcoder's Handbook to learn more about exploitation and overflows. I reached the chapter on Heap Overflows. The book mentions that a heap is split into chunks where each chunk contains ...
4
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1answer
1k views

How to find the stack and other info in a memory dump? ARM

I'm reversing a closed platform to try gain execution using an exploit, a stack overflow. I've been told that (since there are no debuggers) the best way is to use RAM dumps (that I have) to try ...
4
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1answer
109 views

Automatically find intput required to trigger a specific code path in a program

Assuming I have the following scenario: I have spotted a vulnerability in a specific function deep inside of an executable (DLL). To get that code path executed (in a vulnerable context) I need to ...
4
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1answer
659 views

Where to start with iOS debugging?

Long story short, I have always had a jailbroken device, I have written and ported multiple tools to iOS, and have a fair knowledge of objective-C, ROP, and Linux exploitation. I have begun to take an ...
4
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1answer
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Illegal Instruction on sample Buffer Overflow exploit

I have followed the example here. Here is my sample program, "oldskool.c": #include <string.h> void go(char *data) { char name[64]; strcpy(name, data); } int main (int argc, char **...
4
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1answer
277 views

The buffer is too short to insert addresses when exploiting buffer overflow

Newbie here. Sorry for what you about to read . I'm currently working on exploiting a binary on Ubuntu 18.04. Here is some information about the binary: Its checksec information using pwntools: ...
3
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3answers
987 views

Are all the code sequences ended with "ret" potential "gadgets" for ROP attack?

So by reading this rop paper from Dr. Shacham, I know that it is not very hard to find gadgets set that has Turning-complete computation ability. So I am thinking that, in theoretical, are all the ...
3
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1answer
277 views

What is the problem with using inner classes in a class enclosing sensitive information?

I recently heard that using Java inner classes in a class that enclose sensitive information is causing the private data of the class to be changed to protected at the bytecode level (meaning that any ...
3
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1answer
1k views

Why shell code only with nop slide working for me?

I'm trying to understand the exploit for SLMail 5.5. Here is the basic flow : I'm able to control EIP and point to an instruction "JMP ESP" ESP is pointing to the exact start position of my ...
3
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2answers
714 views

Reading Memory to bypass ASLR

Modern exploits use different techniques to bypass ASLR. One of the technique used in some IE exploits is to leak memory using a BSTR overwrite. How can an attacker leak memory, and how can he use it ...
3
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2answers
1k views

gdb on FreeBSD and follow-fork-mode child

Long time ago I noticed that using set follow-fork-mode child in GDB on FreeBSD doesn't really work. This problem occurs very often with some challenges on various Capture The Flag contests. For ...
3
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1answer
1k views

Extract firmware images from COTS embedded devices

I am on the hook to collect some of legacy firmware images from real-world embedded devices. Before digging into it, I am trying to confirm some high-level points. Is it in general possible to ...
3
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1answer
1k views

Use After Free - Example

Use After Free bugs a getting more severe these days. I'm planning to demonstrate Use After Free bug exploitation using VTable overwrite. So, I'm trying to create a ATL ActiveX Control which is ...
3
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1answer
680 views

How should I approach a basic CTF exploitation challenge?

Complete newbie alert so apologies on what you're about to read. I've an executable I'm working with to achieve buffer overflow on. This is for an old CTF that has been and gone but I chose it to ...
3
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2answers
209 views

blackbox vulnerability assessment

I wonder if the tools like AddressSanitizer exist for blackbox analysis. For instance I've fuzzer that can probe some 100 variants per second and after a few seconds crash was detected. Maybe some ...
3
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1answer
215 views

Calculating the page address a buffer belongs to

I was trying out a ROP exploit -- I'm trying to make an mprotect system call using ROP(not a libc call), to try and make the buffer executable. I tried stracing the server process and ran the exploit, ...
3
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1answer
209 views

Shellcode issue

I'm currently trying to understand a peculiar behaviour with a shellcode. When reaching a MOV instruction just before an interrupt the shellcode get modified: As you can see on the radare2 output, my ...
3
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1answer
2k views

explain the vulnerable code used by EternalBlue SMB attack

The recent WannaCry ransomware attack exploited a vulnerability in older Windows SMB code. The presumably reverse-engineered function that has been cited 1 as vulnerable is as follows: unsigned int ...
3
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1answer
248 views

Exploitability of Stack-based Buffer Overflows on functions ending with fclose()

I have been discussing the effectiveness of GNU libc's fclose() function to thwart successful exploitation of trivial vulnerabilities due to segmentation fault when called without a valid pointer to a ...
3
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1answer
256 views

Help on Exploitable response

I have a crash that is exploitable, the information is this: Exploitability Classification: EXPLOITABLE Recommended Bug Title: Exploitable - User Mode Write AV starting at myfunction!mycomponet+...
3
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0answers
309 views

gdb - searching for pointers to a given memory region

Let's suppose there is a memory region that is m'mapped in memory, we need to find its address (which randomly changes, because of ASLR) by following a pointer path, basically, I'm trying to find a ...
3
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2answers
1k views

Finding a place to inject shellcode

I am following the tutorial for ROP Primer, level 0. The tutorial sets the memory at the beginning of [vdso] writeable and executable and copies the shellcode there. I do not know why, but it seems ...
3
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0answers
305 views

I want to know more about how a particular exploit works. How do I do that? [closed]

I am given a VM of a server running a vulnerable version of ProFTP and a attacker VM which exploits the server using an exploit provided with MetaSploit. I need to write a Snort rule to detect ...
2
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3answers
1k views

Why is the value of the ESP register the same every time, when we turnoff the ASLR?

There are many functions running on the system and also they require the ESP register (x86). So if its value becomes constant(by turning off the ASLR), then how could it be possible for every function ...
2
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1answer
2k views

What do these 2 Ghidra warnings mean?

When disassembling ARM binaries in Ghidra, I often see these warnings: /* WARNING: Could not recover jumptable at 0x0747c198. Too many branches */ /* WARNING: Treating ...
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3answers
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exploit - Why not execute shellcode with the inline assembler?

The typical structure of executing shell code is the following-: (The code snippet is taken from here) char shellcode[] = ""; /* global array */ int main (int argc, char **argv) { ...
2
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1answer
836 views

Win7 ASLR bypass

The conditions: say one patched programm has hardcoded address of printf() from dynamically loaded msvcrt80.dll. It works just fine on XP, but Win7 randomizes address space (ASLR), so this trick ...
2
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1answer
3k views

GDB: Could not load shared library symbols

I'm currently having a look at the Damn Vulnerable Router Firmware, and I'm roughly following the description that is given here: https://p16.praetorian.com/blog/getting-started-with-damn-vulnerable-...
2
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1answer
2k views

Basic Buffer Overflow Help

I am currently practicing for a CTF competition and one of the practice challenges is a buffer overflow exploit. Before this challenge I knew absolutely nothing about these exploits, but I've been ...
2
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1answer
1k views

Immunity Debugger - !mona suggest

I have been going through some tutorials for exploit development that use the !pvefindaddr command to help with creating unique patterns and discovering the offset. I know that mona has replaced ...
2
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1answer
390 views

Why is otkloadr.WRAssembly.1 reference present in a office file?

I was working with a RTF file and I found the string "otkloadr.WRAssembly.1" present inside the file in plain sight. I know that many exploits use this for loading the msvcr71.dll (non-ASLR module). ...