CVE-2025-21343 | Windows Web Threat Defense User Service Information Disclosure Vulnerability

Windows Web Threat Defense User Service Information Disclosure Vulnerability

Published: 2025-01-14 Last update: 2025-01-21 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21343 is rated Moderate Risk (63.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 5.39%). EPSS rose +1.81% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-21343

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-15 3.57% 5.39% +1.81%
2 2026-02-22 9.88% 3.57% -6.30%
3 2026-02-13 — 9.88% —

Full EPSS history (24 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21343

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-21343

Affected software / configurations for CVE-2025-21343

Vendor Product Version Raw CPE
microsoft windows_11_22h2 < 10.0.22621.4751 cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
microsoft windows_11_23h2 < 10.0.22631.4751 cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*
microsoft windows_11_24h2 < 10.0.26100.2894 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*

References for CVE-2025-21343

cvelogic Threat Intelligence