CVE-2023-21757 | Windows Layer 2 Tunneling Protocol (L2TP) Denial of Service Vulnerability

Windows Layer 2 Tunneling Protocol (L2TP) Denial of Service Vulnerability

Published: 2023-01-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-21757 is rated Moderate Risk (58.6/100): CVSS High severity, with high exploitation likelihood (EPSS 19.11%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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-2023-21757

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 2026-05-13 23.95% 19.11% -4.84%
2 2026-02-15 23.80% 23.95% +0.15%
3 2026-01-25 — 23.80% —

Full EPSS history (34 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-21757

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:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-21757

Affected software / configurations for CVE-2023-21757

Vendor Product Version Raw CPE
microsoft windows_10 — cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
microsoft windows_10 20h2 cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
microsoft windows_10 21h2 cpe:2.3:o:microsoft:windows_10:21h2:*:*:*:*:*:*:*
microsoft windows_10 22h2 cpe:2.3:o:microsoft:windows_10:22h2:*:*:*:*:*:*:*
microsoft windows_10 1607 cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
microsoft windows_10 1809 cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
microsoft windows_11 — cpe:2.3:o:microsoft:windows_11:-:*:*:*:*:*:arm64:*
microsoft windows_11 — cpe:2.3:o:microsoft:windows_11:-:*:*:*:*:*:x64:*
microsoft windows_11 21h2 cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:arm64:*
microsoft windows_11 21h2 cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:x64:*
microsoft windows_11 22h2 cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:arm64:*
microsoft windows_11 22h2 cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:x64:*
microsoft windows_7 — cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
microsoft windows_8.1 — cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
microsoft windows_rt_8.1 — cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
microsoft windows_server_2008 — cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
microsoft windows_server_2008 r2 cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
microsoft windows_server_2012 — cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
microsoft windows_server_2012 r2 cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
microsoft windows_server_2016 — cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
microsoft windows_server_2019 — cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
microsoft windows_server_2022 — cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*

References for CVE-2023-21757

cvelogic Threat Intelligence