Questions tagged [linux]

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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1answer
191 views

Binary file search tools [closed]

Is there a open-source Linux tool / utility for Linux platform that would recursively search for binary files (executable, shared / static objects, etc), in a folder and display?
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1answer
78 views

Reverse getline(cin, text)

Sup, guys. I'm trying to solve a crackme that was made in C++, and I was able to "recreate" a function call, through the library calls the program made. Here's the piece of code that I'm trying to ...
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1answer
68 views

Why have two symbols tables?

Why have two symbol tables if .symtab already contains everything that's in .dynsym ?
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1answer
108 views

Unexpected SEGFAULT when there's apparently nothing that would cause it

This is a from a CTF problem I'm working on. Hopefully it's appropriate to ask this question here. Above is the GDB output when the segfault goes off. movaps is the offending instruction, meaning ...
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1answer
212 views

why saved rip changed by push?

I am doing a reverse homework. see the following pictures: as can be seen from this picture, before call push touch3, "saved rip" is at 0x5561dca8, which is equal to the current rsp(0x5561dca8). ...
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1answer
59 views

Unknown parameters in custom signal handler on Linux

0x0000000008001946: mov 0xa8(%rdx),%rax 0x000000000800194d: lea 0x28(%rdx),%rsi 0x0000000008001951: lea 0x2(%rax),%rdi 0x0000000008001955: add $0xe,%rax 0x0000000008001959: ...
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1answer
131 views

Question regarding ASLR

If I have a binary file which does not have ASLR enabled. However, the libc file it uses has ASLR enabled, then will the address of system() in libc file be randomized every time? Or the address will ...
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1answer
75 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 ...
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1answer
493 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 ...
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1answer
123 views

3 questions on Assembly - meaning of code, Decompilation in Linux, Higher level perspective,

Following the question here (3 questions on assembly - syntax, meaning, and equivalent in high level code (eg C++)), I would like to know for the same x86 code in AT&T syntax: xor $0x20, (%eax) ...
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1answer
257 views

What checksum algorithm is this network protocol using?

I've been working my way through an undocumented TCP-based protocol by monitoring traffic with tcpdump, Wireshark, and some Python packages (scapy, numpy) with good luck so far, but I've hit a wall ...
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1answer
693 views

Kernel dealing with the section headers in an ELF

I recently read that the kernel and the dynamic loader mostly deal with the program header tables in an ELF file and that assemblers, compilers and linkers deal with the section header tables. The ...
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1answer
182 views

Changing entry-point of and ELF file

I'm trying to conduct a little experiment which basically consists of changing the EP of an ELF file and executing an exit(9) syscall, without returning to the OEP. As shown in the image everything ...
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1answer
42 views

Find out if address store in heap or stack

While dynamic debugging with ida and gdb-server on binary file running on linux , I saw address that store some value. How can I know if this address allocated in stack or in heap?
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1answer
162 views

Fork and Waitpid calls in a CTF linux binary

I'm doing one of my first linux crackmes. In the first blocks of code, it goes inside some anti-debug routine and inside one of those it forks and after it calls a waitpid routine. I can verify it ...
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1answer
620 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 ...
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2answers
715 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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1answer
93 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
235 views

Is it possible to rebuild an nexe file if I can read at arbitrary untrusted memory addresses?

Ok, I’m in a remote situation where I don’t have access to the remote filesystem but where I can run arbitrary python code (except I can’t fork processes and I don’t have access to ulimit and uname). ...
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1answer
865 views

One shellcode works, one doesn't - an issue with exploiting a 64 bit linux binary

I'm working on exploiting a simple 64 bit linux binary. I got control of RIP by exploiting a buffer overflow and using a jmp rsp to get control of the progrm. However, I'm having trouble with the ...
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1answer
232 views

How do I restore modified firmware to a read only mount

I have managed to get a root shell on my web filtering router by plugging into a UART on the PCB which allowed me to see a process (lockbox.bin - ELF executable) running which handles most of the ...
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1answer
1k views

Erase the data from the NVRAM

Cable modem SPI Flash memory have the following structure: 7 cmdlinepart partitions found on MTD device spansion partitions[0] = {.name = U-Boot, .offset = 0x00000000,.size = 0x00020000 (128K) } ...
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1answer
708 views

In-circuit programming of SPI Flash memory

Is it possible to define (using only visual inspection of PCB and multimeter) whether or not SPI Flash memory can be properly programmed keeping the device In-circuit, without desoldering IC from the ...
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1answer
1k views

ldd showing absolute path only

Under what circumstances does the output of ldd have only the absolute path? In the below eg, /usr/lib/arm-linux-gnueabihf/libcofi_rpi.so and /lib/ld-linux-armhf.so.3. pi@raspberrypi ~ $ uname -a ...
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0answers
94 views

Extracting firmware image from binary

I have firmware file in .bin format, but I need get firmware.img image file and Kernel uImage file for reflashing bricked device. How can I get these parts? I used Binwalk to extract content, ...
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Sniffing TCP packets using Wireshark

I am trying to reverse engineer a decoder. The decoder contains a web server that makes sending/receiving information through the Internet possible. To do so I need to sniff the packets that the ...
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0answers
80 views

Decrypt ibt.sfi linux firmware(Intel Wireless 8265 Linux Bluetooth)

Why I want to decrypt: Intel 8265 Bluetooth is likely a RAMUSB device, which needs system to update firmware. I try to transplant this linux firmware to macOS. Problems I met: The macOS BT firmware ...
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1k views

OTOOL alternative for linux

I have a reverse engineering set up on a Mac machine. This set up does some reverse engineering on iOS applications(.ipa files). I'm migrating the setup from Mac to a linux machine. Currently on Mac, ...
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0answers
362 views

Reverse Engineering Linux Core Dump

I have a Linux Core Dump file for a binary (which apparently crashed during execution) file command on the core dump: core.123: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style, from '/...
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0answers
361 views

Passing input to program in Remote Debugging with IDA Pro

I am writing an exploit for a binary on Linux using IDA Pro. This binary, first accepts an input using getchar() and after few more code sections, it accepts a buffer as an input through stdin and it ...
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0answers
925 views

Unable to install ltrace on Kali [closed]

I am kind of stuck with the installation of ltrace on my Kali VM. My /etc/apt/sources.list file is updated with following entry: deb http://http.kali.org/kali kali-rolling main non-free contrib I ...
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146 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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107 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 (...
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613 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 ...
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1answer
152 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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1answer
600 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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183 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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114 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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574 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 ...
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571 views

Reverse Engineering Wifi Chip-set Firmware [closed]

I have Sparrow Wireless Adapter which from Qualcomm originally Wilocity that supports Wifi over 60 GHz (802.11ad or WiGiG). I have the firmware files of the wireless chipset (wil6210.fw and wil6210....
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1answer
3k views

Unable to view stack and memory addresses in IDA Pro [duplicate]

I am debugging a 32-bit ELF executable using remote GDB debugging option of IDA Pro. However, I am unable to view the contents of stack in the stack view. Also, the stack pointer value is: 0xFFFFD328 ...
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1answer
258 views

Mechanisms to stop serial console accepting input on a Linux system?

I am working on a simple embedded system based around an Olinuxino board. This has a serial console header onboard. TX and RX are both connected to the respective pins on the microcontroller (i.e. ...
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0answers
313 views

Why the extracted content differs?

I used binwalk to extract firmware.bin image, the extracted content is squashfs-root dir, and a separate dpc.squashfs file. Then I used sasquatch utility to extract content of dpc.squashfs file, and I ...
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0answers
293 views

Where can i find unix/linux tool for fuzzing for kill-switches? [closed]

I'm looking for linux/unix open-source tools for fuzzing ethernet card for kill-switch packets. https://en.wikipedia.org/wiki/Fuzzing I can imagine how it would be long to brute full of range on ...
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4answers
4k views

Can IDA Pro on Linux disassemble a Windows PE (or Mac OS X app)?

I am thinking of buying IDA Pro for my Linux programming environment after reverse engineering a bit with OllyDBG (under WINE)... But before I endorse into such a costly purchase I ask the following ...
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1answer
6k 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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3answers
4k views

Limited BusyBox shell

I'm testing some embedded device, and there is lack of documentation. When I telnet to device, I get only limited shell. BusyBox v1.19.2 (built-in shell (ash) Enter 'help' for a list of built-in ...
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2answers
1k views

How to know the arguments of a Linux syscall?

To my knowledge, this is a decent resource to know the parameters of a Linux syscall. However, this only lists 32 bit syscalls, not the 64 bit ones. Moreover, the reference doesn't say which register ...
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2answers
351 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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2answers
2k 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/...