What it is
CVE-2024-20481 is an unauthenticated vulnerability affecting Cisco Cisco Adaptive Security Appliance (ASA) Software, Cisco Firepower Threat Defense.... A vulnerability in the Remote Access VPN (RAVPN) service of Cisco...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2024-20481
Cisco Adaptive Security Appliance (ASA) Software Denial of Service
Cisco / Cisco Adaptive Security Appliance (ASA) Software · 9.8.1
- Severity
- CVSS 5.8 · Medium
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 15.9%
- 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 / Cisco Adaptive Security Appliance (ASA) Software 9.8.1.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Cisco Adaptive Security Appliance (ASA) Software Denial of Service
A vulnerability in the Remote Access VPN (RAVPN) service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) of the RAVPN service.
This vulnerability is due to resource exhaustion. An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device. A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device. Depending on the impact of the attack, a reload of the device may be required to restore the RAVPN service. Services that are not related to VPN are not affected.
Cisco Talos discussed these attacks in the blog post Large-scale brute-force activity targeting VPNs, SSH services with commonly used login credentials.
Vendor
Product
Affected
Status
cisco
adaptive_security_appliance_software
9.16.4.39
Affected
cisco
adaptive_security_appliance_software
9.16.4.42
Affected
cisco
adaptive_security_appliance_software
9.16.4.48
Affected
cisco
adaptive_security_appliance_software
9.16.4.55
Affected
cisco
adaptive_security_appliance_software
9.16.4.57
Affected
cisco
adaptive_security_appliance_software
9.16.4.61
Affected
cisco
adaptive_security_appliance_software
9.17.1
Affected
cisco
adaptive_security_appliance_software
9.17.1.7
Affected
cisco
adaptive_security_appliance_software
9.17.1.9
Affected
cisco
adaptive_security_appliance_software
9.17.1.10
Affected
cisco
adaptive_security_appliance_software
9.17.1.11
Affected
cisco
adaptive_security_appliance_software
9.17.1.13
Affected
cisco
adaptive_security_appliance_software
9.17.1.15
Affected
cisco
adaptive_security_appliance_software
9.17.1.20
Affected
cisco
adaptive_security_appliance_software
9.17.1.30
Affected
cisco
adaptive_security_appliance_software
9.17.1.33
Affected
cisco
adaptive_security_appliance_software
9.17.1.39
Affected
cisco
adaptive_security_appliance_software
9.18.1
Affected
cisco
adaptive_security_appliance_software
9.18.1.3
Affected
cisco
adaptive_security_appliance_software
9.18.2
Affected
cisco
adaptive_security_appliance_software
9.18.2.5
Affected
cisco
adaptive_security_appliance_software
9.18.2.7
Affected
cisco
adaptive_security_appliance_software
9.18.2.8
Affected
cisco
adaptive_security_appliance_software
9.18.3
Affected
cisco
adaptive_security_appliance_software
9.18.3.39
Affected
- Published
- 23 Oct 2024
- Exploitation Reported
- 24 Oct 2024
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
nessus_scanner
cisa
edge
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2024-20481
- cisco-sa-asaftd-bf-dos-vDZhLqrW 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 | 2024-10-24 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/209988 | 02 Jun 2025 |
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
5.8
Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS
15.9%
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-2024-20481
Free JSON includes basic KEV fields{
"cve_id": "CVE-2024-20481",
"confidence": "Confirmed",
"cvss_score": 5.8,
"cvss_estimated": false,
"epss_score": 0.15852,
"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.