How severe is CVE-2023-20227?

CVE-2023-20227 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2023-20227 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20227?

CVE-2023-20227 primarily affects Cisco Ios Xe. In total, 96 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-20227?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-20227 published?

CVE-2023-20227 was published on 2023-09-27 and last updated on 2026-06-17.

CVE-2023-20227

CVE-2023-20227 is a high-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-388.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-388
Affected product: Cisco Ios Xe
Published: 2023-09-27
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2023-20227?: CVE-2023-20227 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-20227 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20227?: CVE-2023-20227 primarily affects Cisco Ios Xe. In total, 96 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-20227?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-20227 published?: CVE-2023-20227 was published on 2023-09-27 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-xe-l2tp-dos-eB5tuFmV

Affected products (96)

cpe:2.3:o:cisco:ios_xe:16.8.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1c:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1d:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.1s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.8.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.1s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.5f:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.6:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.9.8:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1c:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1d:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1f:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1g:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.1s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.10.3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.11.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.11.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.11.1b:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.11.1s:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.11.2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.12.1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.12.1a:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios_xe:16.12.1c:*:*:*:*:*:*:*

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