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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Extracted router file execution

I am trying to run an executable file that I dug out from an extracted file system of a DSL modem router. So first of all I needed to either have a MIPS Linux box or take the emulation path. After ...
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0answers
5k views

How to unpack manually an upx packed elf file

I am trying to learn to manually unpack an upx packed elf file. The examples I have found are for Windows, mostly with Ollydbg, and as I see the first step is to look for pushad and popad instructions....
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759 views

Python library for linux to demangle MSVC decorated names

I am looking for a python library for linux which can demangle the function names which are mangled by MSVC. for example : Project!??0?$allocator@D@std@@QAE@XZ to Project!public: __thiscall ...
4
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1answer
206 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: ...
4
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1answer
5k 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, ...
4
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0answers
318 views

Modern equivalent to rsymtab for reconstructing symbol table for statically linked / stripped binaries?

I'm working with a 32-bit ELF binary that (I believe) has been statically linked against a few different third-party libraries. It has also been stripped, so I don't have much to go on with respect to ...
3
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1answer
348 views

Huawei HG8245H, can't read some system files

I have modem Echolife HG8245H (V3R016C10S150). I'm using telnet to connect it. I need to read some files from this modem. There's a shell mode I can enter, but it is nerfed badly: SU_WAP>shell ...
3
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0answers
96 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 ...
3
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1answer
551 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 ...
2
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0answers
23 views

Why PTRACE_POKEDATA returns I/O error?

I learning usage of ptrace. I tried following simple example but raises a I/O Error. I would like to overwrite "Hello, world" (printing string) from other process. A target program prints &...
2
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0answers
116 views

submitting input into AFL fuzzer

I have some questions about the AFL Fuzzer: How does the AFL Fuzzer know where to inject the payload in the code I compile? For instance if I want to inject it in a specific parameter, how do I do it?...
2
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0answers
683 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, ...
2
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1answer
131 views

What is actually loaded here and different hexdump outputs on util-linux hexdump and on cutter and ghidra's hexdump

I was trying to understand what segment of file gets loaded by fourth LOAD header on phdr array. First 6 headers are shown below from readelf Program Headers: Type Offset ...
2
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0answers
671 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 ...
2
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0answers
541 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/...
2
votes
1answer
3k views

How to decrypt the config.bin from ZTE ZXV10 H201L

I have this file from my router its backup of user config,I suppose its compresed with zlib and encrypted with AES. Utility which is resposible to compress it and encrypt it is called cspd. In side ...
2
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0answers
1k views

open a non-standard compression .tar.lzma file extracted from firmware download

We are trying to examine a firmware download for a product we have running on our local network. Using the command binwalk -Me filename we generated a folder that contains the following content: ...
2
votes
2answers
929 views

Finding a place to inject shellcode

I am following the tutorial for ROP Primer, level0. 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 ...
2
votes
0answers
120 views

Trace replayer won't load binary debug information

So I'm debugging a linux application with what I believe DWARF debug information on x86-64 host. Everything is working fine and as expected - the source files are loaded immediately on function ...
2
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0answers
2k views

How to set-up GDB debugging in IDA Pro on Linux via Wine?

I tried running on linux via root terminal: gdbserver --multi localhost:23947 And then at IDA Pro at Wine I use Remote GDB debugger with my local ip and port: However when I start debugging I think ...
2
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0answers
184 views

How can one debug a program that can only be started by other processes?

I am now trying to figure out the innards of a custom made program that I've found difficult to debug using a debugger. The program starts by using a bash script wrapper to process input parameters, ...
2
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0answers
671 views

Flashing NVRAM with U-Boot 1.2.0

I tried to program SPI Flash NVRAM (S25FL064A) from U-boot, but it not allow to write: tftp 0x80000100 nvram.bin cp.b 0x80000100 0x007b0000 0x00050000 There is no error shown after cp.b command, ...
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0answers
64 views

Replacing bytes from start of every function with IDA Pro

I want to fix a .plt segment in IDA Pro by replacing 12 bytes from start of every function in the .plt segment with the ones I specify. I want to just make each function return so I'm replacing ...
1
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0answers
50 views

Same USB packet (Python/user vs C/kernel) but different result

I'm making a Linux module (my first one) for a closed-source, enclosed (no hardware access) device. Using Wireshark I found what to send and where, so I tried the following command in user space ...
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0answers
28 views

Format of Alcatel_Lucent I-240W-A backup file

I am trying to modify the backup file of this router in order to change some configurations. Here is the structure I have until now: 16 bytes of the header, zlib compressed xml with the ...
1
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0answers
132 views

IDA shows MEMORY or unknown references on C std library calls (memset, memcpy, etc.)

I'm currently reversing a Linux 32-bit executable (with a statically linked library included in it) but I'm having a little problem I can't find a solution for. Basically whenever I stumble across a ...
1
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0answers
136 views

Extract files of a SquashFS Filesystem

I already asked a similar question but after a deeper analysis of the filesystem I found out that I misunderstood the problem and that's why I decided to delete the old question and make a new one. I ...
1
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0answers
126 views

IDA remote debugging - non printable characters in parameters

I am trying to remote debug a certain binary which gets user-specified command line arguments, which can be non-printable of course. My goal is the ability to debug with IDA the process with the ...
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0answers
162 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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0answers
990 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
178 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
196 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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0answers
1k 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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0answers
241 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 ...
1
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0answers
719 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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0answers
349 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 ...
0
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0answers
25 views

unix executable Error: Reading 0x1b50 bytes extends past end of file for string table

info on the file it is called ld it is a command for linking elfs called link editor. Does Error: Reading 0x1b50 bytes extends past end of file for string table mean I am missing some kind of offset? ...
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0answers
25 views

Configure Strace do not parse ioctl command

When I run strace strace -fp 123 -o log -e trace="ioctl" I saw ioctl that strace parse the ioctl command , How can I see the number of ioctl command without parsing?
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0answers
76 views

x64dbg for linux executables?

Is there a x64dbg for Linux executables? I really love x64dbg, but in a lot of CTF challenges there are Linux executables and not .exe files or .dll files.
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0answers
28 views

How do I debug Linux kernel modules with IDA?

I'm trying to figure out a workflow for analyzing Linux kernel modules. I want to debug the modules and not just view the disassembly, so I came upon this guide for IDA pro: https://www.hex-rays.com/...
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0answers
24 views

Ollydbg skippingover breakpoint

I am new to the ollydbg world- I am in the middle of injecting shellcode (created with msfvenom...) into a small PE, and during debugging, I can't get it to halt at the breakpoints I set. If I run the ...
0
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1answer
172 views

Need help opening a .img file from a camera firmware (trying to get out of the Meari/Zumimall/PPstrong cloud!)

I've got a cloud-based battery powered camera which I'm really hoping to get out of the cloud with, in order to enable RTSP or ONVIF (or something local!). I've managed to get a .bin file. Binwalk ...
0
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1answer
104 views

ASLR in Linux Vs Windows

I am quite new in binary exploitation. I am doing a lot of beginners exercise here. I am confused about ASLR. I tried some binary exploitation thing in Linux. It was recommended that I should stop ...
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0answers
54 views

Exploit education stack-five: trouble getting the shell

Im trying the phoenix vm, challenge stack-five on exploit.education (http://exploit.education/phoenix/stack-five/). I run onto a problem while exploiting a stack overflow. The challenge is run execve('...
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104 views

Shellcode execution segfault

I have been trying to exploit simple buffer overflow caused by scanf. I'm working on x86 Linux. The point is to spawn a shell. I sucesfully overwritten return address and jumped into my shellcode. But ...
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0answers
50 views

Performing Buffer overflow in Linux

I have buffer overflow in a program i check(it is an array of pointers, and i can overflow the data in the first pointer), but the data i can write is not on the stack, it is on a space the system ...
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0answers
91 views

Bufferoverflow Stack

I want to do a buffer overflow exploit in the stack. For this i read in data via the "gets"-function. void ExploitMe() { char buffer[256]; gets(buffer); } I compile this file with gcc test.c -...
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0answers
1k views

Executing MIPS binaries on Ubuntu Linux

I have a 32-bit MIPS binary and I'm trying to execute it on Ubuntu 64-bit. file command for the binary shows: bin: ELF 32-bit MSB executable, MIPS, MIPS32 rel2 version 1 (SYSV), dynamically linked (...
0
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1answer
217 views

Changing local variable in caller from callee in C?

I'm implementing a function which is going to perform some time-consuming task, and I'd like to hack the benchmarking part a bit by changing the variable indicating the CPU time my function has ...
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0answers
117 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 ...