Web-Exploitation
Found 13 related articles.
Back to Categories- 2025-02-19
Instant - APK Decompilation, LFI via Swagger API, and Solar-PuTTY Backup Decryption
Technical writeup detailing the compromise of the Instant machine. Initial foothold is achieved through static analysis of a downloadable APK file, revealing subdomains and a hardcoded API key. This key is used to exploit a Local File Inclusion (LFI) vulnerability within the authenticated Swagger API (via the logs reading function), leading to SSH key exfiltration and user access. Privilege escalation is achieved by locating, transferring, and decrypting an encrypted Solar-PuTTY sessions backup file, which yields the root password.
- 2024-12-05
TheStickerShop - Stored XSS Leading to Data Exfiltration
Technical writeup detailing the compromise of TheStickerShop. The primary vulnerability exploited is a Stored Cross-Site Scripting (XSS) vulnerability found in the 'Feedback' form on the Python/Werkzeug web server (8080/tcp). The attack leverages a custom JavaScript payload to bypass a 401 Unauthorized error, fetch the restricted 'flag.txt' file, encode its content in Base64, and exfiltrate the data to an attacker-controlled HTTP server via an Image object request.
- 2024-12-04
Vaccine - FTP, PKZIP/MD5 Cracking, SQL Injection via SQLMap, and SUID vi Privesc
Technical writeup detailing the compromise of the Vaccine machine. Initial access is achieved by exploiting Anonymous FTP to retrieve a password-protected PKZIP file, cracking the PKZIP and subsequent MD5 hashes to gain web credentials. Authentication leads to exploiting a blind SQL Injection vulnerability via SQLMap, gaining an OS shell. Privilege escalation is completed by finding plaintext credentials for SSH access, then exploiting the SUID binary 'vi' with specific permissions via the ':shell' command to achieve a root shell.
- 2024-11-27
Alert - XSS to LFI, Hash Cracking, and Group Write Privilege Escalation
Technical writeup detailing the compromise of the Alert Linux machine. Initial access is gained by chaining a Stored XSS vulnerability in the Markdown viewer to a Local File Inclusion (LFI) vulnerability in an internal /messages endpoint. LFI is used to exfiltrate an Apache MD5 hash from the .htpasswd file, which is then cracked via Hashcat to obtain SSH credentials for the 'albert' user. Privilege escalation is achieved by identifying a high-privileged PHP process running as root in a directory with group write permissions (management), which the 'albert' user belongs to. The configuration.php file is modified to set the SUID bit on /bin/bash, granting a root shell.
- 2024-11-23
Responder - LFI/RFI Chain to NTLMv2 Hash Capture and WinRM Access
Technical writeup detailing the initial compromise of the Responder machine. The attack chain involves exploiting a Local File Inclusion (LFI) vulnerability in a PHP application, escalating it to an RFI-style attack by injecting a UNC path to force an SMB authentication attempt. The resulting NTLMv2 hash is captured using the Responder tool, cracked with Hashcat, and used to gain full remote access via Evil-WinRM on port 5985.
- 2024-11-21
Three - S3 Bucket Misconfiguration and Remote Code Execution via AWS CLI
Technical writeup detailing the compromise of the Three machine. The methodology involves identifying an exposed subdomain (s3.thetoppers.htb) pointing to an AWS S3 bucket. Exploitation is achieved by leveraging a misconfigured access policy via the AWS CLI to perform an arbitrary file upload of a PHP webshell. Remote Code Execution (RCE) is then established using the webshell, leading to full system access as the www-data user.
- 2024-11-20
Crocodile - FTP Anonymous Login and Credential Disclosure
Technical writeup detailing the compromise of the Crocodile machine. Initial access is achieved by exploiting the Anonymous FTP login vulnerability on the vsFTPd 3.0.3 service (21/tcp) to disclose files containing credentials (allowed.userlist and allowed.userlist.passwd). Web enumeration via Gobuster reveals a hidden '/login.php' endpoint. The disclosed 'admin' credentials are used to access the web panel and retrieve the flag, completing the box.
- 2024-11-18
Appointment - Authentication Bypass via SQL Injection (SQLi)
Technical writeup detailing the compromise of the Appointment machine. The primary vulnerability is an Authentication Bypass via SQL Injection (SQLi) affecting the web application's login form. By injecting the payload 'admin'#' into the username field, the SQL query is manipulated to bypass the password check, allowing unauthenticated access as the admin user to retrieve the flag.
- 2024-11-06
Whiterose - IDOR, EJS SSTI (CVE-2022-29078), and Sudoedit Bypass (CVE-2023-22809)
Technical writeup detailing the compromise of the Whiterose machine. Initial access involves subdomain enumeration via wFuzz and exploiting an IDOR vulnerability to retrieve privileged user credentials. This leads to a Server-Side Template Injection (SSTI) RCE via CVE-2022-29078 (EJS Template Engine vulnerability). Privilege escalation is achieved by exploiting the Sudoedit vulnerability CVE-2023-22809 to gain root access via modifying the /etc/sudoers file.
- 2024-10-31
StellarJWT - JWT Exploitation and Chained SUID Privilege Escalation
Technical writeup detailing the compromise of the 'StellarJWT' challenge. The methodology involves identifying and decoding an exposed JSON Web Token (JWT) for user enumeration, followed by a dictionary attack using Hydra for SSH access. Privilege escalation is achieved through a chained exploitation of NOPASSWD SUID binaries: using 'socat' for horizontal movement and 'chown' for '/etc/passwd' modification to gain final root access.
- 2024-10-21
Chemistry - Pymatgen RCE (CVE-2024-23346), SSH Port Forwarding, and aiohttp LFI (CVE-2024-23334)
Technical writeup detailing the compromise of the Chemistry machine. Initial access (RCE) is gained by exploiting CVE-2024-23346, an arbitrary code execution vulnerability in the pymatgen library via a malicious .CIF file upload, leading to a low-privileged shell. Privilege escalation is achieved by locating hidden credentials in a SQLite database, gaining SSH access, and then using SSH Port Forwarding to access an internal web service. The final step involves exploiting CVE-2024-23334, a critical path traversal vulnerability in aiohttp/3.9.1, to perform Local File Inclusion (LFI) and read the /etc/shadow file for root access.
- 2024-10-20
TwoMillion - API Enumeration, Information Disclosure, and Kernel Privilege Escalation (CVE-2023-0386)
Technical writeup detailing the compromise of the TwoMillion machine. Initial access involves decoding ROT13-encrypted data from JavaScript to find an API endpoint, followed by manipulating API parameters to gain administrator privileges via Insecure Direct Object Reference (IDOR), leading to a reverse shell injection. Local Privilege Escalation is achieved by disclosing plaintext credentials from a '.env' file for SSH access, and finally, exploiting the unpatched Linux Kernel vulnerability, CVE-2023-0386 (OverlayFS/FUSE), to gain root privileges.
- 2024-10-01
WalkingCMS - WordPress Exploitation via Theme Editor and SUID Privilege Escalation
Technical writeup detailing the compromise of the WalkingCMS challenge. Initial access involves enumerating a WordPress installation via Gobuster, credential cracking using WPScan, and achieving a reverse shell by modifying the theme's index.php file. Final root access is achieved by exploiting a vulnerable SUID binary, '/usr/bin/env', using standard Linux privilege escalation techniques.