CVE-2023-20227

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain L2TP packets. An attacker could exploit this vulnerability by sending crafted L2TP packets to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.

Published: 2023-09-27 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-20227 is rated Moderate Risk (50.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.65%). 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-2023-20227

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 2026-06-15 0.36% 0.65% +0.29%
2 2026-01-25 0.47% 0.36% -0.11%
3 2025-11-21 — 0.47% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-20227

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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 4.0 [email protected]
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-2023-20227

Affected software / configurations for CVE-2023-20227

Vendor Product Version Raw CPE
cisco ios_xe 16.8.1 cpe:2.3:o:cisco:ios_xe:16.8.1:*:*:*:*:*:*:*
cisco ios_xe 16.8.1a cpe:2.3:o:cisco:ios_xe:16.8.1a:*:*:*:*:*:*:*
cisco ios_xe 16.8.1b cpe:2.3:o:cisco:ios_xe:16.8.1b:*:*:*:*:*:*:*
cisco ios_xe 16.8.1c cpe:2.3:o:cisco:ios_xe:16.8.1c:*:*:*:*:*:*:*
cisco ios_xe 16.8.1d cpe:2.3:o:cisco:ios_xe:16.8.1d:*:*:*:*:*:*:*
cisco ios_xe 16.8.1e cpe:2.3:o:cisco:ios_xe:16.8.1e:*:*:*:*:*:*:*
cisco ios_xe 16.8.1s cpe:2.3:o:cisco:ios_xe:16.8.1s:*:*:*:*:*:*:*
cisco ios_xe 16.8.2 cpe:2.3:o:cisco:ios_xe:16.8.2:*:*:*:*:*:*:*
cisco ios_xe 16.8.3 cpe:2.3:o:cisco:ios_xe:16.8.3:*:*:*:*:*:*:*
cisco ios_xe 16.9.1 cpe:2.3:o:cisco:ios_xe:16.9.1:*:*:*:*:*:*:*
cisco ios_xe 16.9.1a cpe:2.3:o:cisco:ios_xe:16.9.1a:*:*:*:*:*:*:*
cisco ios_xe 16.9.1b cpe:2.3:o:cisco:ios_xe:16.9.1b:*:*:*:*:*:*:*
cisco ios_xe 16.9.1s cpe:2.3:o:cisco:ios_xe:16.9.1s:*:*:*:*:*:*:*
cisco ios_xe 16.9.2 cpe:2.3:o:cisco:ios_xe:16.9.2:*:*:*:*:*:*:*
cisco ios_xe 16.9.3 cpe:2.3:o:cisco:ios_xe:16.9.3:*:*:*:*:*:*:*
cisco ios_xe 16.9.4 cpe:2.3:o:cisco:ios_xe:16.9.4:*:*:*:*:*:*:*
cisco ios_xe 16.9.5 cpe:2.3:o:cisco:ios_xe:16.9.5:*:*:*:*:*:*:*
cisco ios_xe 16.9.5f cpe:2.3:o:cisco:ios_xe:16.9.5f:*:*:*:*:*:*:*
cisco ios_xe 16.9.6 cpe:2.3:o:cisco:ios_xe:16.9.6:*:*:*:*:*:*:*
cisco ios_xe 16.9.7 cpe:2.3:o:cisco:ios_xe:16.9.7:*:*:*:*:*:*:*
cisco ios_xe 16.9.8 cpe:2.3:o:cisco:ios_xe:16.9.8:*:*:*:*:*:*:*
cisco ios_xe 16.10.1 cpe:2.3:o:cisco:ios_xe:16.10.1:*:*:*:*:*:*:*
cisco ios_xe 16.10.1a cpe:2.3:o:cisco:ios_xe:16.10.1a:*:*:*:*:*:*:*
cisco ios_xe 16.10.1b cpe:2.3:o:cisco:ios_xe:16.10.1b:*:*:*:*:*:*:*
cisco ios_xe 16.10.1c cpe:2.3:o:cisco:ios_xe:16.10.1c:*:*:*:*:*:*:*
cisco ios_xe 16.10.1d cpe:2.3:o:cisco:ios_xe:16.10.1d:*:*:*:*:*:*:*
cisco ios_xe 16.10.1e cpe:2.3:o:cisco:ios_xe:16.10.1e:*:*:*:*:*:*:*
cisco ios_xe 16.10.1f cpe:2.3:o:cisco:ios_xe:16.10.1f:*:*:*:*:*:*:*
cisco ios_xe 16.10.1g cpe:2.3:o:cisco:ios_xe:16.10.1g:*:*:*:*:*:*:*
cisco ios_xe 16.10.1s cpe:2.3:o:cisco:ios_xe:16.10.1s:*:*:*:*:*:*:*
cisco ios_xe 16.10.2 cpe:2.3:o:cisco:ios_xe:16.10.2:*:*:*:*:*:*:*
cisco ios_xe 16.10.3 cpe:2.3:o:cisco:ios_xe:16.10.3:*:*:*:*:*:*:*
cisco ios_xe 16.11.1 cpe:2.3:o:cisco:ios_xe:16.11.1:*:*:*:*:*:*:*
cisco ios_xe 16.11.1a cpe:2.3:o:cisco:ios_xe:16.11.1a:*:*:*:*:*:*:*
cisco ios_xe 16.11.1b cpe:2.3:o:cisco:ios_xe:16.11.1b:*:*:*:*:*:*:*
cisco ios_xe 16.11.1s cpe:2.3:o:cisco:ios_xe:16.11.1s:*:*:*:*:*:*:*
cisco ios_xe 16.11.2 cpe:2.3:o:cisco:ios_xe:16.11.2:*:*:*:*:*:*:*
cisco ios_xe 16.12.1 cpe:2.3:o:cisco:ios_xe:16.12.1:*:*:*:*:*:*:*
cisco ios_xe 16.12.1a cpe:2.3:o:cisco:ios_xe:16.12.1a:*:*:*:*:*:*:*
cisco ios_xe 16.12.1c cpe:2.3:o:cisco:ios_xe:16.12.1c:*:*:*:*:*:*:*
cisco ios_xe 16.12.1s cpe:2.3:o:cisco:ios_xe:16.12.1s:*:*:*:*:*:*:*
cisco ios_xe 16.12.1t cpe:2.3:o:cisco:ios_xe:16.12.1t:*:*:*:*:*:*:*
cisco ios_xe 16.12.1w cpe:2.3:o:cisco:ios_xe:16.12.1w:*:*:*:*:*:*:*
cisco ios_xe 16.12.1x cpe:2.3:o:cisco:ios_xe:16.12.1x:*:*:*:*:*:*:*
cisco ios_xe 16.12.1y cpe:2.3:o:cisco:ios_xe:16.12.1y:*:*:*:*:*:*:*
cisco ios_xe 16.12.1z1 cpe:2.3:o:cisco:ios_xe:16.12.1z1:*:*:*:*:*:*:*
cisco ios_xe 16.12.1z2 cpe:2.3:o:cisco:ios_xe:16.12.1z2:*:*:*:*:*:*:*
cisco ios_xe 16.12.2 cpe:2.3:o:cisco:ios_xe:16.12.2:*:*:*:*:*:*:*
cisco ios_xe 16.12.2a cpe:2.3:o:cisco:ios_xe:16.12.2a:*:*:*:*:*:*:*
cisco ios_xe 16.12.2s cpe:2.3:o:cisco:ios_xe:16.12.2s:*:*:*:*:*:*:*
cisco ios_xe 16.12.3 cpe:2.3:o:cisco:ios_xe:16.12.3:*:*:*:*:*:*:*
cisco ios_xe 16.12.3s cpe:2.3:o:cisco:ios_xe:16.12.3s:*:*:*:*:*:*:*
cisco ios_xe 16.12.4 cpe:2.3:o:cisco:ios_xe:16.12.4:*:*:*:*:*:*:*
cisco ios_xe 16.12.4a cpe:2.3:o:cisco:ios_xe:16.12.4a:*:*:*:*:*:*:*
cisco ios_xe 16.12.5 cpe:2.3:o:cisco:ios_xe:16.12.5:*:*:*:*:*:*:*
cisco ios_xe 16.12.5a cpe:2.3:o:cisco:ios_xe:16.12.5a:*:*:*:*:*:*:*
cisco ios_xe 16.12.6 cpe:2.3:o:cisco:ios_xe:16.12.6:*:*:*:*:*:*:*
cisco ios_xe 16.12.6a cpe:2.3:o:cisco:ios_xe:16.12.6a:*:*:*:*:*:*:*
cisco ios_xe 16.12.7 cpe:2.3:o:cisco:ios_xe:16.12.7:*:*:*:*:*:*:*
cisco ios_xe 16.12.8 cpe:2.3:o:cisco:ios_xe:16.12.8:*:*:*:*:*:*:*
cisco ios_xe 17.1.1 cpe:2.3:o:cisco:ios_xe:17.1.1:*:*:*:*:*:*:*
cisco ios_xe 17.1.1a cpe:2.3:o:cisco:ios_xe:17.1.1a:*:*:*:*:*:*:*
cisco ios_xe 17.1.1s cpe:2.3:o:cisco:ios_xe:17.1.1s:*:*:*:*:*:*:*
cisco ios_xe 17.1.1t cpe:2.3:o:cisco:ios_xe:17.1.1t:*:*:*:*:*:*:*
cisco ios_xe 17.1.3 cpe:2.3:o:cisco:ios_xe:17.1.3:*:*:*:*:*:*:*
cisco ios_xe 17.2.1 cpe:2.3:o:cisco:ios_xe:17.2.1:*:*:*:*:*:*:*
cisco ios_xe 17.2.1a cpe:2.3:o:cisco:ios_xe:17.2.1a:*:*:*:*:*:*:*
cisco ios_xe 17.2.1r cpe:2.3:o:cisco:ios_xe:17.2.1r:*:*:*:*:*:*:*
cisco ios_xe 17.2.1v cpe:2.3:o:cisco:ios_xe:17.2.1v:*:*:*:*:*:*:*
cisco ios_xe 17.2.2 cpe:2.3:o:cisco:ios_xe:17.2.2:*:*:*:*:*:*:*
cisco ios_xe 17.2.3 cpe:2.3:o:cisco:ios_xe:17.2.3:*:*:*:*:*:*:*
cisco ios_xe 17.3.1 cpe:2.3:o:cisco:ios_xe:17.3.1:*:*:*:*:*:*:*
cisco ios_xe 17.3.1a cpe:2.3:o:cisco:ios_xe:17.3.1a:*:*:*:*:*:*:*
cisco ios_xe 17.3.1w cpe:2.3:o:cisco:ios_xe:17.3.1w:*:*:*:*:*:*:*
cisco ios_xe 17.3.1x cpe:2.3:o:cisco:ios_xe:17.3.1x:*:*:*:*:*:*:*
cisco ios_xe 17.3.1z cpe:2.3:o:cisco:ios_xe:17.3.1z:*:*:*:*:*:*:*
cisco ios_xe 17.3.2 cpe:2.3:o:cisco:ios_xe:17.3.2:*:*:*:*:*:*:*
cisco ios_xe 17.3.2a cpe:2.3:o:cisco:ios_xe:17.3.2a:*:*:*:*:*:*:*
cisco ios_xe 17.3.3 cpe:2.3:o:cisco:ios_xe:17.3.3:*:*:*:*:*:*:*
cisco ios_xe 17.3.4 cpe:2.3:o:cisco:ios_xe:17.3.4:*:*:*:*:*:*:*

References for CVE-2023-20227

cvelogic Threat Intelligence