What it is
CVE-2023-20109 is a vulnerability affecting Cisco IOS, Cisco IOS XE Software. A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2023-20109
IOS Denial of Service
Cisco / IOS · 12.4(24)T
- Severity
- CVSS 6.6 · Medium
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 2.3%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Cisco / IOS 12.4(24)t.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
IOS Denial of Service
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.
Vendor
Product
Affected
Status
Cisco
IOS
15.5(2)T4
Affected
Cisco
IOS
15.5(1)T4
Affected
Cisco
IOS
15.2(2)EA
Affected
Cisco
IOS
15.2(2)EA1
Affected
Cisco
IOS
15.2(2)EA2
Affected
Cisco
IOS
15.2(3)EA
Affected
Cisco
IOS
15.2(4)EA
Affected
Cisco
IOS
15.2(4)EA1
Affected
Cisco
IOS
15.2(2)EA3
Affected
Cisco
IOS
15.2(4)EA3
Affected
Cisco
IOS
15.2(5)EA
Affected
Cisco
IOS
15.2(4)EA4
Affected
Cisco
IOS
15.2(4)EA5
Affected
Cisco
IOS
15.2(4)EA6
Affected
Cisco
IOS
15.2(4)EA7
Affected
Cisco
IOS
15.2(4)EA8
Affected
Cisco
IOS
15.2(4)EA9
Affected
Cisco
IOS
15.2(4)EA9a
Affected
Cisco
IOS
15.5(3)M
Affected
Cisco
IOS
15.5(3)M1
Affected
Cisco
IOS
15.5(3)M0a
Affected
Cisco
IOS
15.5(3)M2
Affected
Cisco
IOS
15.5(3)M3
Affected
Cisco
IOS
15.5(3)M4
Affected
Cisco
IOS
15.5(3)M4a
Affected
- Published
- 27 Sep 2023
- Exploitation Reported
- 10 Oct 2023
- Attack vector
- Remote
- Complexity
- High
- Privileges
- High
- User interaction
- None
Tags
ios
nessus_scanner
edge
cisa
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2023-20109
- cisco-sa-getvpn-rce-g8qR68sx sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2023-10-10 00:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
Nessus template detected 02 Jun 2025.
View Nessus template (opens in new tab)Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nessus | https://www.tenable.com/plugins/nessus/183215 | 02 Jun 2025 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
6.6
Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
2.3%
Weaknesses
Timeline
From disclosure to observed exploitation
-
Nessus plugin available
Scanner coverage available
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2023-20109
Free JSON includes basic KEV fields{
"cve_id": "CVE-2023-20109",
"confidence": "Confirmed",
"cvss_score": 6.6,
"cvss_estimated": false,
"epss_score": 0.02344,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.