What is CVE-2023-20109?

CVE-2023-20109 is a medium-severity vulnerability in Cisco iOS Xe Software, classified under Out-of-bounds Write. CVSS score: 6.6/10. Published 2023-09-27.

How severe is CVE-2023-20109?

Medium severity. CVSS v3 base score is 6.6 out of 10.

Is CVE-2023-20109 known to be exploited?

Yes. CVE-2023-20109 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-10), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.

Buffer overflow in Cisco iOS Xe Software

CVE-2023-20109

A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute arbitrary code on an affected device or cause the device to crash. This vulnerability is due to insufficient validation of attributes in the Group Domain of Interpretation (GDOI) and G-IKEv2 protocols of the GET VPN feature. An attacker could exploit this vulnerability by either compromising an installed key server or modifying the configuration of a group member to point to a key server that is controlled by the attacker. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a denial of service (DoS) condition. For more information, see the Details ["#details"] section of this advisory.

Vulnerability class: Buffer Overflow

EPSS: 0.023 (82.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Cisco Ios Xe Software — versions 3.7.0S, 3.7.1S, 3.7.2S
Cisco Ios — versions 15.6\(2\)sp7, 15.2(4)ec2, 15.0(2)SE10a
Cisco Ios_xe — versions 3.3.0sg, 3.3.1sg, 3.3.2sg

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2023-10-10. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2023-10-31.

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

psirt@cisco.com (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2023-20109?: CVE-2023-20109 is a medium-severity vulnerability in Cisco iOS Xe Software, classified under Out-of-bounds Write. CVSS score: 6.6/10. Published 2023-09-27.
How severe is CVE-2023-20109?: Medium severity. CVSS v3 base score is 6.6 out of 10.
Is CVE-2023-20109 known to be exploited?: Yes. CVE-2023-20109 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-10-10), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.