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A free and open source POSIX compatible operating system with a monolithic kernel and a kernel module system. Originally created by Linus Torvalds.

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55 views

PIE bypass in /system/bin/linker [closed]

I tried to remove PIE error from my linker by this manual, but I can not find "data xref" line near this error. What to do? .rodata:0000B1F9 aErrorOnlyPosit DCB "error: only position independent ...
2
votes
1answer
42 views

extract zImage from MS-DOS executable

I have an aarch64 kernel image with the following magic number: root@localhost:/# cat msImage|xxd -l4 00000000: 4d5a 0091 MZ.. root@localhost:/# file msImage ...
0
votes
2answers
86 views

How to interpret disassembled MIPS code?

I have disassembled MIPS binary with raw opcodes. How to interpret, for example, these lines: Disassembly of section .data: 00000000 <.data>: ... ... f864: 30a5ffff sd ra,-23248(...
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0answers
19 views

Cannot open '/proc/…/maps': No such file or directory in radare2 debug mode

When I try to load a program to radare2 debug mode, most of the time I get the following error: $sudo r2 -d a.out Hello world!= attach 2851 2851 Cannot open '/proc/2851/maps': No such file or ...
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0answers
21 views

Immunity error BB010002

I am trying to make this exploit work and having some difficulty. So I skipped to a 'fixed' version of it from here and the only thing I changed was the shell code: https://github.com/cokebottle/oscp-...
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0answers
52 views

Obscure router refuses to flash OpenWrt

This is a very obscure Chinese router from a brand called Wavlink. It's the Model: WN529R2/WN529R2P. It's web interface was pretty limited and wouldn't allow firmware modifications. I found GND/Tx/Rx/...
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votes
0answers
28 views

Read SPI Flash memory blocks

I have device with embedded eCos RTOS and SPI Flash memory. Flash Device Information: CFI Compliant: no Command Set: Generic SPI Flash Device/Bus Width: x16 Little Word Endian: ...
3
votes
1answer
65 views

Radare2 debugging - How to get into lazy imported functions?

I have a linux binary that imports functions from an external library (shared object). The functions are lazy loaded and not available when rip is at @main or @entry. When i step into such a function (...
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1answer
166 views

Dynamic Analysis on ELF using IDA

On Linux, while generally reversing ELF files and dynamic analyzing (like step into, step over, break-point, inspecting registers value, memory etc) I use gdb or radare2 which provides dynamic ...
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votes
2answers
111 views

Looking for reverse engneer online course [duplicate]

I looking for online reverse engeneer course. Course that study ida,reverse and patch for windows/ linux. Working with ida and another tool. I like many videos lesons. Do you know one?
0
votes
0answers
144 views

IDA remote debugger on linux “input is a dynamic library…”

I am trying to understand how to debug with the remote debugger of IDA on linux. I tried to debug the bof challenge of pwnable.kr (http://pwnable.kr/bin/bof). It is a 32-bit ELF, so I could not run ...
0
votes
0answers
24 views

Is it possible from usermode to see if a process has opened /proc/$currentprocpid/mem?

Im looking into Linux anti debugging techniques and I know some of the more common tricks like ptraceing yourself, but is it possible to see if a program has opened the current process virtual ...
0
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0answers
204 views

Extract Icons from PE file with python on Linux

I am trying to write some code to extract all icons from a PE file using PEfile on linux The PE file that gives me a challenge has more icons in the RT_ICON section then listed in the RT_GROUP_ICON ...
0
votes
1answer
441 views

Adding additional language to Linux based Firmware of Volkswagen Car Radio

I'm owning a CarPlay head unit from Volkswagen called RCD330 plus. It is possible to upgrade/downgrade to any available firmwares. For example here are two firmware versions: http://rcd330plus.com/rcd/...
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0answers
51 views

Unsquashfs fails partways with gzip error code -5

I have been trying to unsquash a system.sfs file in order to modify the directories. however, unsquashfs system.sfs returns the following output: Parallel unsquashfs: Using 8 processors 1 inodes (...
0
votes
1answer
87 views

Linux x64 Disassembly: single movzwl operand question

A quick question regarding a movzwl instruction which do not behave as I expected. here is the disassembled code: movzwl (%rax),%eax Before the instruction, rax is 0x7fffffffe410 and point to 0x5 ...
1
vote
1answer
263 views

Rebuilding firmware back to binary file

I used Binwalk to extract firmware files, extracted content include 2 folders and one binary file. squashfs-root _351C.extracted 351C Squashfs-root contains file system, '_351C.extracted' folder ...
2
votes
1answer
81 views

ARM system crashes after changing stack address

-- Edit with latest update on the problem, it is not solved yet :( -- While playing with an ARM embedded Linux system (Version 3.8.13), out of curiosity, I created a small "debug" kernel module. ...
3
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2answers
394 views

ARM64 syscalls table

I wonder if there some syscall table for Linux ARM64 architecture? I found syscall table for Linux ARM32 and many other architectures, but the problem still exists. Does anyone know where can I find ...
0
votes
1answer
146 views

x64 Linux reverse-engineering - understanding asm code and inject eax

In a rootme exercise, i'm trying to bypass the control impleted to protect a "read" function. You'll find enclosed the code i'm refering to. As you may understand, i can inject data (with limitations) ...
2
votes
1answer
415 views

Disassemblers resolving (ELF) section names

I'm working with linux executables and was just wondering how it is that section names are resolved to addresses upon disassembly of an ELF. For example take some random disassembly output from ...
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votes
1answer
431 views

Unpacking firmware

I have a ROM dump firmware which must be reversed (as a task). Binwalk output: DECIMAL HEXADECIMAL DESCRIPTION -------------------------------------------------------------------------------...
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0answers
343 views

TP-Link encrypted backup file TX-VG1530

I have been trying to wrap my head round this stuff so bear with me. I have a Tp-Link TX-VG1530. From the gui you can download the config file however the file is encrypted, I include a portion of ...
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0answers
305 views

My core dump's backtrace stops to a signal handler, what can I do?

I obtained an ELF core dump that was provoked by fuzzing a proprietary server. As I do not have access anymore to the machine that hosted this server, and the server is part of a tightly coupled set ...
1
vote
1answer
292 views

Basic shellcode doesn't work when read from stdin

I am working on a basic shellcode that will spawn a shell after getting called in a 32-bit program. Here is the shellcode i'm using: xor %eax,%eax push %eax push $0x68732f2f push $...
1
vote
1answer
71 views

Redirecting Program Output from /dev/*char_device* to Text File

I am currently trying to reverse an IoT machine running the 2.6 Linux Kernel on which I have root. On this machine, software writes to /dev/some_device to control what I believe to be are GPIO pins ...
6
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3answers
6k views

Help reversing end-of-life'd Logitech Link. How to get Flash Contents

See Update below. I got an email from Logitech that they are End of Lifing their Harmony Link product (see https://community.logitech.com/s/question/0D55A0000745EkCSAU/harmony-link-eos-or-eol). So I ...
11
votes
1answer
1k views

Debugging with radare2 using two terminals

I have been trying to figure this out for quite some time now, and would really need some help. Firstly, some intro: I am running the newest version of radare2 from Github on a 64bit Ubuntu 16.04 and ...
5
votes
1answer
177 views

Need help with a USB gaming mouse

I have a Chinese USB gaming mouse (04d9:a070) which has 4 color modes and 4 light levels. I know for a fact that this mouse is capable for showing at least 5 different color so it must be an RGB led (...
0
votes
0answers
434 views

jffs2 extraction

I took the firmware from the EEPROM of my IP camera, it has jffs2 file system. once i extract it there is no file system, the entire folder is empty. what will be the reason and any suggestion? ...
2
votes
1answer
405 views

How can I view the dynamic symbol table of a running process?

For any dynamic executable on Linux there is a dynamic linker that stores the current symbol bindings somewhere. So when a new library is loaded it knows whether to bind the symbol or not. For ...
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1answer
3k views

Reverse engineering a golang binary file

I compiled docker by myself with some modifications. I would like to perform some static analysis to the binary. Mostly to see which parts of the code take more memory, etc. It's on linux (elf). Any ...
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0answers
106 views

JTAG pinout for Linksys E4200v2/EA4500

Can anyone specify an actual JTAG pinout for Linksys E4200v2/EA4500 router? The EA4500 and the EA4200v2 are actually identical hardware. There is unpopulated 8-pin JTAG header on PCB, 4x2 rows. s10....
1
vote
1answer
91 views

library issue when running mips binary in a chrooted environment

Background In my endeavor to RE my router, I'm trying to emulate a router's firmware inside a QEMU MIPS system. I have debian-mips installed to a virtual disk that runs just fine. Its a MIPS32 Big ...
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2answers
383 views

IDA Pro - Applying function signatures

I have three files: ELF executable, ELF dynamically linked library (.so), C headers file (.h) with function signatures and related structures for that library. #1 imports a number of functions from #...
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0answers
47 views

methods for identifying deliberately unmagiked filesystem

I am trying to restore a system from backups around some obnoxious copy protection. It is a Linux system from an vendor that does not appear to comply with the GPL and has overwritten the header of ...
8
votes
1answer
2k views

Reverse Engineering ZyXel C1100Z modem firmware

first time post so please bear with me. For days I have been trying to bypass a password my ISP has added to their remote CLI with no luck. I have a Zyxel C1100Z DSL modem that I've purchased from ...
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1answer
176 views

Practicing what SHOULD be a simple crackme. Program calls strlen() but never returns

I'm trying out a crackme from the "LSE CTF" called "Blue Box" worth only 10 points. I've attempted this inside GDB and radare2... It is very simple, takes one argument and first checks to make sure ...
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1answer
803 views

IDA Pro debugging: follow child process

I'm reverse engineering a malware that creates a number of child processes and I'm trying to do dynamic analysis of the ELF binary with IDA Pro and IDA's Local Linux Debugger, but I can't get IDA to ...
2
votes
1answer
111 views

Determining an application's library call behaviour

I have a closed source Linux library libfoo that makes calls into another closed source library libbar for additional (mostly unneeded) features. However, I can't use libbar for ethical reasons, so I ...
1
vote
1answer
267 views

How to extract an unknown archive file? Currently Im trying to open *.pak (P5CK)

I have a console game called Timesplitters Future Perfect(iso file). I were able to extract and got bunch of files. *.pak being one type I would like to open and see. I opened up a hex editor and saw ...
1
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1answer
322 views

Why always get the message “Illegal Instruction (core dumped)”?

I tried to exploiting buffer overflow. In the exploit code I use the Aleph-One shellcode. "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\...
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vote
0answers
155 views

X64 ASSEMBLY - Cannot run compiled and linked raw shellcode in Windows

After using metasploit's windows/x64/meterpreter/reverse_tcp shellcode on my windows 10 machine (with AVs turned off), I decided to try to create a hand-made polymorphic, null-free and custom-encoded ...
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vote
1answer
90 views

Is it possible to restart over a program by calling an entry point function?

I was wondering if it was possible to restart a program (ignoring previously mapped files) with different argument by either calling main() or a glibc entry point function.
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1answer
127 views

Length requirement on IOLI crackme input

So I'm just starting to learn reverse engineering and binary exploitation and going through the RPI course where the first lab set is drawn from the IOLI crackmes available on Github. I could post all ...
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0answers
279 views

Is there a way to debug an elf file that runs with no problems with damaged header?

My question is general, but to have an example to work with, let us take one from Whirlwind Tutorial. ; tiny.asm BITS 32 org 0x00010000 db 0x7F, "ELF" ; ...
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2answers
1k views

Changing Entrypoint in ELF executable

I wrote some code that does the following: Searches for and finds an offset in a binary file to add code (looks for a sequence of 00s I can overwrite). Then, I change the entrypoint of the ELF to ...
0
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0answers
67 views

Transferring control of ptrace to another process

I have a program that runs fine most of the time, but all of a sudden "overheats". When this happens, all of a sudden resources just go up rapidly in a matter of seconds until the system locks up. I ...
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0answers
110 views

What is the name of this technique?

A while back, on a Linux system, I found a strange binary being executed at seemingly random times with some strange arguments, briefly appearing in ps. There was nothing to be found at the usual ...
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0answers
343 views

ZyXEL P-2812HNU-F1, replacing the U-Boot on the board

I want flash regular(non branded) firmware on ZyXEL P-2812HNU-F1 router, which have branded version of firmware (customized for local MSO provider). To do this, I should first replace the U-Boot image ...