CVE-2023-20227

highpriority · track · 30EPSS 0.009 · 58 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.87% (58th) EPSS
CVSS 7.5 · high
Is it mine?
302 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.6
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–8.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.18.6highAV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 4
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-388USCWE-404US
04

affected products (302)

Products and version ranges known to be affected.

showing 20 of 302
05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2023-2509Cisco IOS XE: Mehrere SchwachstellenDeutsch2023-09-27csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Cisco IOS XE ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder beliebigen Code auszuführen.

  • cisco-sa-ios-xe-l2tp-dos-eB5tuFmVCisco IOS XE Software Layer 2 Tunneling Protocol Denial of Service Vulnerability2023-09-27csaf · cisco_csafUS

    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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2023 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2023 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74916"].

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcisco_csafNVDCVE.orgMITRE
published 2023-09-27modified 2026-06-17
08

references (4)

External citations — patches, advisories, analysis.

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