GHSA-763X-Q553-5W8V
Vulnerability from github – Published: 2025-07-02 21:32 – Updated: 2025-07-02 21:32A security bypass vulnerability exists in Google Chrome AppBound cookie encryption mechanism due to insufficient validation of COM server paths during inter-process communication. A local low-privileged attacker can hijack the COM class identifier (CLSID) registration used by Chrome's elevation service and point it to a non-existent or malicious binary. When this hijack occurs, Chrome silently falls back to the legacy cookie encryption mechanism (protected only by user-DPAPI), thereby enabling cookie decryption by any user-context malware without SYSTEM-level access. This flaw bypasses the protections intended by the AppBound encryption design and allows cookie theft from Chromium-based browsers.
Confirmed in Google Chrome with AppBound Encryption enabled. Other Chromium-based browsers may be affected if they implement similar COM-based encryption mechanisms.
{
"affected": [],
"aliases": [
"CVE-2025-34090"
],
"database_specific": {
"cwe_ids": [
"CWE-276"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-02T20:15:30Z",
"severity": "CRITICAL"
},
"details": "A security bypass vulnerability exists in Google Chrome AppBound cookie encryption mechanism due to insufficient validation of COM server paths during inter-process communication. A local low-privileged attacker can hijack the COM class identifier (CLSID) registration used by Chrome\u0027s elevation service and point it to a non-existent or malicious binary. When this hijack occurs, Chrome silently falls back to the legacy cookie encryption mechanism (protected only by user-DPAPI), thereby enabling cookie decryption by any user-context malware without SYSTEM-level access. This flaw bypasses the protections intended by the AppBound encryption design and allows cookie theft from Chromium-based browsers.\n\nConfirmed in Google Chrome with AppBound Encryption enabled. Other Chromium-based browsers may be affected if they implement similar COM-based encryption mechanisms.",
"id": "GHSA-763x-q553-5w8v",
"modified": "2025-07-02T21:32:00Z",
"published": "2025-07-02T21:32:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-34090"
},
{
"type": "WEB",
"url": "https://vulncheck.com/advisories/google-chrome-appbound-cookie-encryption"
},
{
"type": "WEB",
"url": "https://www.cyberark.com/resources/threat-research-blog/c4-bomb-blowing-up-chromes-appbound-cookie-encryption"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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",
"type": "CVSS_V4"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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