feat: PoC write on target stdout and resume

This commit is contained in:
əlemi 2023-03-27 02:43:29 +02:00
parent 67cd814c99
commit 2a9ce2e8c7
Signed by: alemi
GPG key ID: A4895B84D311642C
2 changed files with 47 additions and 18 deletions

View file

@ -1,9 +1,9 @@
mod syscalls;
use std::ffi::c_void;
use nix::{Result, {sys::{ptrace, wait::waitpid}, unistd::Pid}};
use nix::{Result, {sys::{ptrace, wait::waitpid}, unistd::Pid}, libc::{PROT_READ, PROT_WRITE, MAP_PRIVATE, MAP_ANON}};
use clap::Parser;
use syscalls::prepare_exit;
use syscalls::{prepare_mmap, prepare_write};
#[derive(Parser, Debug)]
#[command(author, version, about, long_about = None)]
@ -16,19 +16,42 @@ struct NeedleArgs {
word: u32,
}
pub fn write_buffer(pid: Pid, addr: usize, payload: &[u8], word:u32) -> Result<()> {
let mut buffer = payload.to_vec();
pub fn send_str(pid: Pid, syscall_addr: u64, data: &str) -> Result<usize> {
let mut regs = ptrace::getregs(pid)?;
regs.rip = syscall_addr;
prepare_mmap(&mut regs, 0, data.len(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0xFFFFFFFFFFFFFFFF, 0);
ptrace::setregs(pid, regs)?;
ptrace::step(pid, None)?;
waitpid(pid, None)?;
let zone_addr = ptrace::getregs(pid)?.rax as usize;
write_buffer(pid, zone_addr, data.as_bytes(), 32)?; // TODO word size!
Ok(zone_addr)
}
while buffer.len() % word as usize != 0 {
buffer.push(0); // pad with zeros because we copy chunks of size 'word'
pub fn read_buffer(pid: Pid, addr: usize, size: usize, word: u32) -> Result<Vec<u8>> {
let mut out = vec![];
for i in (0..size).step_by((word/8) as usize) {
let data = ptrace::read(pid, (addr + i) as *mut c_void)?;
for j in 0..(word/8) as usize {
out.push(((data >> (j * 8)) & 0xFF) as u8);
}
}
for i in (0..buffer.len()).step_by(word as usize) {
unsafe {
let offset = (addr + i) as *mut c_void;
let data = (buffer.as_ptr().add(i)) as *mut c_void;
ptrace::write(pid, offset, data)?;
Ok(out)
}
pub fn write_buffer(pid: Pid, addr: usize, payload: &[u8], word:u32) -> Result<()> {
let step = word / 8;
let mut at = addr;
for chunk in payload.chunks(step as usize) {
let mut buf : u64 = 0;
for (i, c) in chunk.iter().enumerate() {
buf |= (*c as u64) << (i * 8);
}
unsafe { ptrace::write(pid, at as *mut c_void, buf as *mut c_void)?; }
at += step as usize;
}
Ok(())
@ -40,6 +63,7 @@ pub fn pwn(pid: Pid, _word_size: usize) -> Result<()> {
let mut insn_addr;
let mut curr_instr;
// seek to syscall
loop {
prev_regs = ptrace::getregs(pid)?;
insn_addr = prev_regs.rip;
@ -64,19 +88,24 @@ pub fn pwn(pid: Pid, _word_size: usize) -> Result<()> {
// ptrace::write(pid, insn_addr, syscall_insn.as_slice().as_ptr() as *mut c_void)?;
// }
let msg = send_str(pid, insn_addr, "injected!\n\0")?;
let mut call_regs = prev_regs.clone();
// call_regs.rip = insn_addr;
prepare_exit(&mut call_regs, 69);
call_regs.rip = insn_addr;
prepare_write(&mut call_regs, 1, msg, 10);
ptrace::setregs(pid, call_regs)?;
ptrace::step(pid, None)?;
waitpid(pid, None)?;
// println!("Written payload to stdout on tracee");
// restore code and registers
// unsafe {
// ptrace::write(pid, insn_addr, prev_instr.as_ptr() as *mut c_void)?;
// }
// ptrace::setregs(pid, prev_regs)?;
ptrace::setregs(pid, prev_regs)?;
Ok(())
}

View file

@ -11,8 +11,8 @@ fn prepare_for_syscall(regs: &mut user_regs_struct, rax: u64, rdi: u64, rsi: u64
}
#[allow(unused)]
pub fn prepare_mmap(regs: &mut user_regs_struct, addr: u64, len: u64, prot: u64, flags: u64, fd: u64, off: u64) {
prepare_for_syscall(regs, 9, addr, len, prot, flags, fd, off);
pub fn prepare_mmap(regs: &mut user_regs_struct, addr: u64, len: usize, prot: i32, flags: i32, fd: u64, off: u64) {
prepare_for_syscall(regs, 9, addr, len as u64, prot as u64, flags as u64, fd, off);
}
#[allow(unused)]
@ -21,8 +21,8 @@ pub fn prepare_open(regs: &mut user_regs_struct, filename: &str, flags: u64, mod
}
#[allow(unused)]
pub fn prepare_write(regs: &mut user_regs_struct, fd: u64, buf: &str, count: usize) {
prepare_for_syscall(regs, 1, fd, buf.as_ptr() as u64, count as u64, 0, 0, 0);
pub fn prepare_write(regs: &mut user_regs_struct, fd: u64, buf: usize, count: usize) {
prepare_for_syscall(regs, 1, fd, buf as u64, count as u64, 0, 0, 0);
}
#[allow(unused)]