CVE-2025-21311 | Windows NTLM V1 Elevation of Privilege Vulnerability

Windows NTLM V1 Elevation of Privilege Vulnerability

Published: 2025-01-14 Last update: 2025-01-24 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-21311 is rated High Risk (71.6/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 4.42%). EPSS rose +1.14% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize 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-2025-21311

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 2026-06-05 3.28% 4.42% +1.14%
2 2026-02-22 6.84% 3.28% -3.56%
3 2026-01-20 — 6.84% —

Full EPSS history (24 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-21311

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2025-21311

OS Trackers for CVE-2025-21311

vendor priority summary link
debian not yet assigned CVE-2025-21311 not yet assigned priority: Debian including 1 source packages (squid), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2025-21311
ubuntu medium CVE-2025-21311 medium priority: Ubuntu including 2 source packages (squid, squid3), 11 status rows across 7 suites (bionic, focal, jammy, noble, plucky, upstream, xenial): ignored 6, DNE 3, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2025-21311

Affected software / configurations for CVE-2025-21311

Vendor Product Version Raw CPE
microsoft windows_11_24h2 < 10.0.26100.2894 cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*
microsoft windows_server_2022_23h2 < 10.0.25398.1369 cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*
microsoft windows_server_2025 < 10.0.26100.2894 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

References for CVE-2025-21311

cvelogic Threat Intelligence