Questions tagged [radare2]

Opensource reverse engineering framework to disassemble, debug, analyze, manipulate binary files and more.

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1answer
123 views

how to use core file in radare2?

In gdb i can backtrace with core file and executable file. It seems radare2 can read core file. like this $ r2 core Setting up coredump: asm.arch <-> x86 and asm.bits <-> 64 Setting up ...
6
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1answer
2k views

radare2 ascii graph to image?

After analysing a function and pressing VV to go into graph mode, is it somehow possible to export/render the whole graph to an image? I have some huge main functions and it would be nice to have it ...
-1
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2answers
243 views

RFLAGS info and Radare?

Stepping through instructions I can see the result of rflags change, rflags C1PSI rflags 1PZI Is there anything that expands this into the appropriate flags. I know Z is Zero-flag, and P is Parity, ...
2
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0answers
48 views

radare2 wrong output

I saw rasm2 giving different output each time for x64 Take a look at this: C:\WINDOWS\system32>rasm2 -a x86 -b 64 -d "41f6c7FF" test r15b, 0xff C:\WINDOWS\system32>rasm2 -a x86 -b 64 "test ...
2
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0answers
35 views

Invert stack view in radare2

Is it possible to invert the stack view when debugging in radare2 such that higher addresses are at the top?
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1answer
87 views

Radare2 doesn't update current address, when single-step debugging using `ds`?

Radare2 doesn't update current address, when single-step debugging using ds? I'm debugging an ELF binary on Linux using single-step (ds). The problem is that the current address at the prompt doesn't ...
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1answer
195 views

ELF binary corrupted after adding instruction in non-executable section

I've been messing around a little with Radare2 trying to master binary exploitation and patching. I added a couple of assembly instructions to an x86 elf binary in a non-executable section of the file,...
1
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1answer
55 views

radare2 shows main function arguments argv as pointer to char on the stack, not as pointer to pointer to char

Well, I've been digging around process command line arguments as well as environment variables a bit these last days, especially looking up the way main function arguments were pushed onto the stack. ...
2
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3answers
757 views

Radare produces a bunch of `add byte [rax], al`, but why?

What does a bunch of add byte [rax], al mean? I see a lot of memory addressing point to specific parts of the shared library (.dll) that have for instance, this... 0x10064faf8 0000 ...
0
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1answer
36 views

How to view registers values in string

Is it possible that radare2 will show registers values also in strings ? For example, when I run ar I am getting the liste of registers and I have: rax = 0x000000042 Is there a way to also show ...
5
votes
1answer
477 views

Radare2- How to see stdout in Visual Mode

How can I display any standard write in visual mode. For example if I run dc command it runs the program normally and displays all the text normally. But if I enter visual mode with V< enter > ...
2
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1answer
204 views

Radare2 Disassembler How Do You Organize Visual Panels (V!)?

I would like to use Radare2 to learn about how C is assembled into assembly but I am having trouble with the layout. I think the V! mode would be very handy as you can watch the registers update as ...
2
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0answers
38 views

function call trace with radare2 or break on all function call

I want to script with python using r2pipe. Is there a way that when debugging I can break on each call function, thus I can get the parameter? What's more, I won't jump into system library. Or is ...
4
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1answer
87 views

How do I type in hex input into radare2 debug mode?

#include<stdio.h> #include<stdlib.h> int main() { puts("Enter input: "); char buf[100]; fgets(buf, 100, stdin); printf("%s", buf); } Suppose I am debugging a program, such ...
0
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1answer
29 views

How to increment and decrement machine code in radare2?

I watched a video (I believe it was a talk by the author of radare2) of how to increment machine code in radare2 very easily, simply by hitting 'c' and then using + and - to respectively increment and ...
2
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1answer
43 views

How to write sequence of machine code in radare2?

I know how to write an opcode and how to increment and decrement machine code using plus and minus keys. However, how do I write a sequence of machine code at an offset? E.g. if I want to write five ...
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2answers
106 views

crackme disassembly - are these local variables ever initialized?

I'm working on a crackme, where the objective is to find the valid password given a program. I'm using radare2 to reverse engineering the program. To do so, I need to enter a password that forces this ...
2
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2answers
655 views

Writing a file with radare2 `w`?

Radare2 supports a w which writes a string. w foobar write string 'foobar' However, it doesn't seem to work for me, $ touch foo $ radare2 ./foo w foobar The file foo remains empty. Am ...
7
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1answer
140 views

Radare2 Call $+5 and register-based cross-references not found

I have a library of ~65MB which uses this "technique" as a kind of PIC. First, it gets some kind of base address (it is always the same): 0x00708497 e800000000 call 0x70849c 0x0070849c ...
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0answers
136 views

Illegal instruction fault in stack based buffer overflow

I wrote this short C program to practice buffer overflow exploits: #include <stdio.h> #include <string.h> #include <stddef.h> #include <inttypes.h> char *decode(char *s){ ...
2
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1answer
55 views

When reopening file lose all information in radare2

I have problem with my radare2, when I try to reopen file in debug mode (ood) my radare loses all informations about that file. any help to avoid this?
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1answer
87 views

How to use aaa in radare2 while in -d (debug) mode?

This might be a stupid question, but I am trying to learn by myself and I encountered a problem which I cannot solve for the life of me. I tried googling and I can't find anything relevant, so here ...
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2answers
294 views

Radare2 - How to scale panel height in visual panels mode?

Visual Panels Mode (V!): I need more space (height) for RegisterRefs and less for Registers (its 50% blank anyway). How can i do that? I can move the vertical split with H and L but i couldn't find ...
1
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1answer
41 views

Passing hex strings to Radare2

I can quickly test hex string arguments in gdb like this: r $'\x61\x61\x61\x61' I'd like to do something similar in radare2 but all I can figure out is regular strings: doo aaaa I tried this but ...
2
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1answer
56 views

How to examine/edit stack memory contents using radare2 in debug mode?

How can i examine/edit stack contents using radare2, just like gdb ? Is there a way to examine memory using $rbp or $rsp register like below. x $rbp-10 <--- something like this which can dump from ...
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0answers
45 views

How to debug programs that load from another one? with radare2/gdb

I'm reversing engendering a plugin. This plugin is loaded into memory by the main program. I disassemble the plugin with radare2 but I don't know how to debug it. I try with gdb but same problem. I ...
1
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1answer
50 views

Is there watchpoints in radare2?

Is there any way to put breakpoints in radare2 that trigger when an address is read/write? In GDB those are call watchpoints ('rwatch' or 'awatch") I got this from radare2 [0xB7F08810]> !dr? ...
2
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1answer
157 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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1answer
138 views

Reassembling reversed ASM

I am trying to reassemble code reversed from an executable using radare2. I have managed to extract the asm and am using nasm for reassembling. The question is, the code also contains commands like ...
2
votes
3answers
212 views

Debugging a process running in a Virtual Machine with Radare2?

Is there anyway to debug a process running on a Virtual Machine (guest) with Radare2 from the host? I'm currently using VirtualBox. It provides a built in debugger. I'm not sure if it's possible for ...
5
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1answer
16k views

How to debug (like gdb) with radare2?

I am new to radare2 and Linux. I got problem with r2. As the title states it, many tutorials, articles, videos about r2 are just about disassembling programs, and read assembly codes. But, I want ...
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1answer
32 views

What this “arw” line means when processing Mach-0 file with Radare2 or Rabin2?

Processing a Mach-0 file with Rabin2 I'm obtaining the following result: $ rabin2 -I mybinaryfile arw ...
1
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1answer
65 views

debugging with radare2

I am using radare2 for disassemble an x86 binary: $ r2 ./mynbinary [0x00001000]> aaa ... [0x00001000]> pdf ;-- section..text: ;-- section.LOAD1: ;-- rip: / (...
1
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1answer
105 views

Setting register names in Radare2

I am reverse-engineering an 8051 architecture program of a specific chip. The disassembly naturally doesn't contain any function names, and the register names are minimal. For example, address 0xb3 is ...
2
votes
1answer
155 views

How to print eax value with Radare2?

I am solving a crack me challenge but I am stuck. The challenge executes several jne tests. The first test is the simpliest but I don't arrive to print the eax value to know the content of cmp ...
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2answers
75 views

What does layout of Cutter/Radare2's function dissasembly mean?

Cutter displays functions like this: I'm having trouble understanding the layout of the functions For example: What does 184 mean? What does the green | mean at the beginning of each line? Why ...
1
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1answer
82 views

How to set a breakpoint in an execve'd program in radare2?

If I have a program A, which uses execve to run program B. How can I set a breakpoint in program B's main routine if I'm debugging program A? After a certain point in the execve routine, program B ...
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0answers
107 views

Password is right, but still wrong?

i am trying to find the password of a binary with radare2 - a crackme again :-) I already thought I've found the password ('pass'), but this seems to be not the right one. Or there is a trick I didn'...
2
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1answer
97 views

Radare2 does not display the entire assembler code

I am trying to solve this ELF - Ptrace crack me. Here are the commands I use : I start radare2 with the crack me as argument. radare2 ch3.bin I decide to go to the main and print the assembly code ...
0
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1answer
616 views

How to print the value of register with Radare 2

I am trying to solve this ELF - Ptrace challenge. I use Radare 2. This is the commands I execute to print the assembly code. radare2 ch3.bin [0x080482f0]> aaa [[anal.jmptbl] Missing cjmp bb in ...
6
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2answers
1k views

what is radare2's equivalent to GDB's 'find &system,+9999999,“/bin/sh”'

What is radare2's equivalent to GDB's find &system,+9999999,"/bin/sh"?
2
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1answer
60 views

radare2 how to interpret ascii-art color bars?

I can't understand the meaning of ascii-art color bars. what is the meaning of the # charaters? [0x08000210]> iS= 00 0x08000000 |---------------------------------| 0x08000000 0 --- 01 ...
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1answer
324 views

Radare2 create section

Radare2 has S* commands, that can show, delete, modify sections. Is it possible to create new section in executable file and save it?
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1answer
119 views

Function names syntax returned by radare2's afl?

Radare2's afl command returns function names with a specific syntax that I could not find documentation on: For example: radare2 -2 -A -q -c "aflj" C:/Windows/system32/advapi32.dll 0x77cce13c 22 ...
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1answer
199 views

Print string at address with radare2

I have created a very basic golang program which display a message with fmt.Println(). Here is what is see in radare2: lea rcx, obj.main.statictmp_0 ; 0x4c84b0 ; "y[K" mov qword [local_48h], rcx lea ...
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2answers
90 views

How does this command modify the condition?

I'm new to radare2 here. Just started learning and I was trying out a challenge. What does the 3 columns in the radare2 visual mode represent? May I know how the command below: wa je 0x400976 @...
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1answer
86 views

rip adress not visible with dr command

I just finished this challenge. This is the content of main function : [0x08048a86]> pdf / (fcn) main 417 | main (int argc, char **argv, char **envp); | ; var int local_16h @ ebp-0x16 |...
2
votes
1answer
66 views

Why does -A (aaa) analysis show much more information, when using the -d (debug) CLI option in Radare2?

Why does -A (aaa) analysis show much more information, when using the -d (debug) CLI option in Radare2? I'm using the newest version of Radare2 to analyze the Windows application. As can be seen ...
2
votes
1answer
70 views

Debug point not hit with radare2

I am doing this reverse engenering challenge. I executed theses commands to analyse the main function : radare2.exe ch15.exe aaa s main pdf This is the output of the pdf command : [0x004017b8]> ...
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2answers
458 views

What means sym prefix before functions name in radare2

What means sym prefix in disassembly? For examle, sym.main?