webhard

Ghost Board

0xl4ugh

Task: Retrieve a flag from a randomly-named file on a Spring Boot server with AngularJS frontend and Puppeteer bot. Solution: Chain AngularJS CSTI via HTML entity bypass to steal admin JWT, exploit Thymeleaf __${...}__ preprocessing SSTI for SpEL injection, use Spring DefaultResourceLoader for file read, and leak the flag from /proc/1/environ.

$ ls tags/ techniques/

file_read ssti jwt xss csti thymeleaf angularjs spel

angularjs_cstihtml_entity_bypassthymeleaf_preprocessing_sstispel_injectionspring_resourceloader_file_readproc_environ_leak

Analysis

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

🔒

Permission denied (requires tier.pro)

Sign in to access full writeups

Create a free account with GitHub, then upgrade to Pro.

$ssh [email protected]