CVE-2023-20109
MediumExploitedPublic exploitA 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…
Published Sep 29, 2023 · Updated Oct 21, 2025
Key Facts
Patch immediately- CVE-2023-20109 is a medium-severity vulnerability (CVSS 6.6 v3.1) affecting IOS (Cisco), IOS Xe (Cisco), Cisco IOS XE Software.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 27, 2023. Public exploit code is available.
- EPSS estimates a 2.5% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
6.6
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
2.5%
Higher than 84.3% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2023-20109 brief as a PDF
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Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Oct 10, 2023 | Oct 31, 2023 | Not reported |
| Industry KEV feed | Sep 27, 2023 | Oct 31, 2023 | Not reported |
| CIRCL KEV | Oct 10, 2023 | Oct 31, 2023 | Not reported |
| ENISA EUVD | Oct 10, 2023 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
1,040 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOSCisco | 12.4\(22\)md, 12.4\(22\)md1, 12.4\(22\)md2, 12.4\(22\)mda, 12.4\(22\)mda1, 12.4\(22\)mda2, 12.4\(22\)mda3, 12.4\(22\)mda4 | n/a |
| IOS XeCisco | 16.10.1, 16.10.1a, 16.10.1b, 16.10.1c, 16.10.1d, 16.10.1e, 16.10.1f, 16.10.1g | n/a |
| Cisco IOS XE Software | >= 3.7.0S | n/a |
Timeline
Added to Industry KEV feed
Sep 27, 2023
Publicly disclosed
Sep 29, 2023
Added to CISA KEV
Oct 10, 2023
Added to CIRCL KEV
Oct 10, 2023
Added to ENISA EUVD
Oct 10, 2023
Last updated
Oct 21, 2025
Weakness Type
- CWE-787 Out-of-bounds Write
References
- advisorycisco-sa-getvpn-rce-g8qR68sx
- advisoryhttps://sec.cloudapps.cisco.com/security/center/psirtrss20/CiscoSecurityAdvisory.xml#details
- advisoryhttps://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74916
- advisoryhttps://www.cybersecurity-help.cz/vdb/SB2023092818
- advisoryhttps://www.cybersecurity-help.cz/vulnerabilities/81248/
FAQ
Common Questions.
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.
Affected: IOS (Cisco) versions 12.4\(22\)md, 12.4\(22\)md1, 12.4\(22\)md2, 12.4\(22\)mda, 12.4\(22\)mda1, 12.4\(22\)mda2, 12.4\(22\)mda3, 12.4\(22\)mda4; IOS Xe (Cisco) versions 16.10.1, 16.10.1a, 16.10.1b, 16.10.1c, 16.10.1d, 16.10.1e, 16.10.1f, 16.10.1g; Cisco IOS XE Software versions >= 3.7.0S. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Sep 27, 2023.
Yes. It was added on Oct 10, 2023 with a federal remediation due date of Oct 31, 2023.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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