What it is
CVE-2024-20481 is an unauthenticated vulnerability affecting Cisco Adaptive Security Appliance (ASA) Software, Cisco Firepower Threat Defense Software. 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 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. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV.
Who is affected?
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
Affected
adaptive_security_appliance_software
9.8.1
9.8.1.5
9.8.1.7
9.8.2
9.8.2.8
9.8.2.14
9.8.2.15
9.8.2.17
9.8.2.20
9.8.2.24
9.8.2.26
9.8.2.28
9.8.2.33
9.8.2.35
9.8.2.38
9.8.3.8
9.8.3.11
9.8.3.14
9.8.3.16
9.8.3.18
9.8.3.21
9.8.3
9.8.3.26
9.8.3.29
9.8.4
9.8.4.3
9.8.4.7
9.8.4.8
9.8.4.10
9.8.4.12
9.8.4.15
9.8.4.17
9.8.2.45
9.8.4.25
9.8.4.20
9.8.4.22
9.8.4.26
9.8.4.29
9.8.4.32
9.8.4.33
9.8.4.34
9.8.4.35
9.8.4.39
9.8.4.40
9.8.4.41
9.8.4.43
9.8.4.44
9.8.4.45
9.8.4.46
9.8.4.48
9.12.1
9.12.1.2
9.12.1.3
9.12.2
9.12.2.4
9.12.2.5
9.12.2.9
9.12.3
9.12.3.2
9.12.3.7
9.12.4
9.12.3.12
9.12.3.9
9.12.2.1
9.12.4.2
9.12.4.4
9.12.4.7
9.12.4.10
9.12.4.13
9.12.4.8
9.12.4.18
9.12.4.24
9.12.4.26
9.12.4.29
9.12.4.30
9.12.4.35
9.12.4.37
9.12.4.38
9.12.4.39
9.12.4.40
9.12.4.41
9.12.4.47
9.12.4.48
9.12.4.50
9.12.4.52
9.12.4.54
9.12.4.55
9.12.4.56
9.12.4.58
9.12.4.62
9.12.4.65
9.12.4.67
9.14.1
9.14.1.10
9.14.1.6
9.14.1.15
9.14.1.19
9.14.1.30
9.14.2
9.14.2.4
9.14.2.8
9.14.2.13
9.14.2.15
9.14.3
9.14.3.1
9.14.3.9
9.14.3.11
9.14.3.13
9.14.3.18
9.14.3.15
9.14.4
9.14.4.6
9.14.4.7
9.14.4.12
9.14.4.13
9.14.4.14
9.14.4.15
9.14.4.17
9.14.4.22
9.14.4.23
9.14.4.24
9.15.1
9.15.1.7
9.15.1.10
9.15.1.15
9.15.1.16
9.15.1.17
9.15.1.1
9.15.1.21
9.16.1
9.16.1.28
9.16.2
9.16.2.3
9.16.2.7
9.16.2.11
9.16.2.13
9.16.2.14
9.16.3
9.16.3.3
9.16.3.14
9.16.3.15
9.16.3.19
9.16.3.23
9.16.4
9.16.4.9
9.16.4.14
9.16.4.18
9.16.4.19
9.16.4.27
9.16.4.38
9.16.4.39
9.16.4.42
9.16.4.48
9.16.4.55
9.16.4.57
9.16.4.61
9.17.1
9.17.1.7
9.17.1.9
9.17.1.10
9.17.1.11
9.17.1.13
9.17.1.15
9.17.1.20
9.17.1.30
9.17.1.33
9.17.1.39
9.18.1
9.18.1.3
9.18.2
9.18.2.5
9.18.2.7
9.18.2.8
9.18.3
9.18.3.39
9.18.3.46
9.18.3.53
9.18.3.55
9.18.3.56
9.18.4
9.18.4.5
9.18.4.8
9.18.4.22
9.18.4.24
9.19.1
9.19.1.5
9.19.1.9
9.19.1.12
9.19.1.18
9.19.1.22
9.19.1.24
9.19.1.27
9.19.1.28
9.19.1.31
9.20.1
9.20.1.5
9.20.2
9.20.2.10
9.20.2.21
Affected
cisco
Affected
firepower_threat_defense_software
6.2.3
6.2.3.10
6.2.3.11
6.2.3.12
6.2.3.13
6.2.3.14
6.2.3.15
6.2.3.16
6.2.3.17
6.2.3.18
6.2.3.2
6.2.3.3
6.2.3.4
6.2.3.5
6.2.3.6
6.2.3.7
6.2.3.8
6.2.3.9
6.4.0
6.4.0.1
6.4.0.10
6.4.0.11
6.4.0.12
6.4.0.13
6.4.0.14
6.4.0.15
6.4.0.16
6.4.0.17
6.4.0.2
6.4.0.3
6.4.0.4
6.4.0.5
6.4.0.6
6.4.0.7
6.4.0.8
6.4.0.9
6.6.0
6.6.0.1
6.6.1
6.6.3
6.6.4
6.6.5
6.6.5.1
6.6.5.2
6.6.7
6.6.7.1
6.6.7.2
6.7.0
6.7.0.1
6.7.0.2
6.7.0.3
7.0.0
7.0.0.1
7.0.1
7.0.1.1
7.0.2
7.0.2.1
7.0.3
7.0.4
7.0.5
7.0.6
7.0.6.1
7.0.6.2
7.1.0
7.1.0.1
7.1.0.2
7.1.0.3
7.2.0
7.2.0.1
7.2.1
7.2.2
7.2.3
7.2.4
7.2.4.1
7.2.5
7.2.5.1
7.2.5.2
7.2.6
7.2.7
7.2.8
7.2.8.1
7.3.0
7.3.1
7.3.1.1
7.3.1.2
7.4.0
7.4.1
7.4.1.1
Affected
Cisco
Affected
Cisco Adaptive Security Appliance (ASA) Software
9.8.1
9.8.1.5
9.8.1.7
9.8.2
9.8.2.8
9.8.2.14
9.8.2.15
9.8.2.17
9.8.2.20
9.8.2.24
9.8.2.26
9.8.2.28
9.8.2.33
9.8.2.35
9.8.2.38
9.8.3.8
9.8.3.11
9.8.3.14
9.8.3.16
9.8.3.18
9.8.3.21
9.8.3
9.8.3.26
9.8.3.29
9.8.4
9.8.4.3
9.8.4.7
9.8.4.8
9.8.4.10
9.8.4.12
9.8.4.15
9.8.4.17
9.8.2.45
9.8.4.25
9.8.4.20
9.8.4.22
9.8.4.26
9.8.4.29
9.8.4.32
9.8.4.33
9.8.4.34
9.8.4.35
9.8.4.39
9.8.4.40
9.8.4.41
9.8.4.43
9.8.4.44
9.8.4.45
9.8.4.46
9.8.4.48
9.12.1
9.12.1.2
9.12.1.3
9.12.2
9.12.2.4
9.12.2.5
9.12.2.9
9.12.3
9.12.3.2
9.12.3.7
9.12.4
9.12.3.12
9.12.3.9
9.12.2.1
9.12.4.2
9.12.4.4
9.12.4.7
9.12.4.10
9.12.4.13
9.12.4.8
9.12.4.18
9.12.4.24
9.12.4.26
9.12.4.29
9.12.4.30
9.12.4.35
9.12.4.37
9.12.4.38
9.12.4.39
9.12.4.40
9.12.4.41
9.12.4.47
9.12.4.48
9.12.4.50
9.12.4.52
9.12.4.54
9.12.4.55
9.12.4.56
9.12.4.58
9.12.4.62
9.12.4.65
9.12.4.67
9.14.1
9.14.1.10
9.14.1.6
9.14.1.15
9.14.1.19
9.14.1.30
9.14.2
9.14.2.4
9.14.2.8
9.14.2.13
9.14.2.15
9.14.3
9.14.3.1
9.14.3.9
9.14.3.11
9.14.3.13
9.14.3.18
9.14.3.15
9.14.4
9.14.4.6
9.14.4.7
9.14.4.12
9.14.4.13
9.14.4.14
9.14.4.15
9.14.4.17
9.14.4.22
9.14.4.23
9.14.4.24
9.15.1
9.15.1.7
9.15.1.10
9.15.1.15
9.15.1.16
9.15.1.17
9.15.1.1
9.15.1.21
9.16.1
9.16.1.28
9.16.2
9.16.2.3
9.16.2.7
9.16.2.11
9.16.2.13
9.16.2.14
9.16.3
9.16.3.3
9.16.3.14
9.16.3.15
9.16.3.19
9.16.3.23
9.16.4
9.16.4.9
9.16.4.14
9.16.4.18
9.16.4.19
9.16.4.27
9.16.4.38
9.16.4.39
9.16.4.42
9.16.4.48
9.16.4.55
9.16.4.57
9.16.4.61
9.17.1
9.17.1.7
9.17.1.9
9.17.1.10
9.17.1.11
9.17.1.13
9.17.1.15
9.17.1.20
9.17.1.30
9.17.1.33
9.17.1.39
9.18.1
9.18.1.3
9.18.2
9.18.2.5
9.18.2.7
9.18.2.8
9.18.3
9.18.3.39
9.18.3.46
9.18.3.53
9.18.3.55
9.18.3.56
9.18.4
9.18.4.5
9.18.4.8
9.18.4.22
9.18.4.24
9.19.1
9.19.1.5
9.19.1.9
9.19.1.12
9.19.1.18
9.19.1.22
9.19.1.24
9.19.1.27
9.19.1.28
9.19.1.31
9.20.1
9.20.1.5
9.20.2
9.20.2.10
9.20.2.21
Affected
Cisco
Affected
Cisco Firepower Threat Defense Software
6.2.3
6.2.3.1
6.2.3.2
6.2.3.3
6.2.3.4
6.2.3.5
6.2.3.6
6.2.3.7
6.2.3.8
6.2.3.10
6.2.3.11
6.2.3.9
6.2.3.12
6.2.3.13
6.2.3.14
6.2.3.15
6.2.3.16
6.2.3.17
6.2.3.18
6.6.0
6.6.0.1
6.6.1
6.6.3
6.6.4
6.6.5
6.6.5.1
6.6.5.2
6.6.7
6.6.7.1
6.6.7.2
6.4.0
6.4.0.1
6.4.0.3
6.4.0.2
6.4.0.4
6.4.0.5
6.4.0.6
6.4.0.7
6.4.0.8
6.4.0.9
6.4.0.10
6.4.0.11
6.4.0.12
6.4.0.13
6.4.0.14
6.4.0.15
6.4.0.16
6.4.0.17
6.4.0.18
6.7.0
6.7.0.1
6.7.0.2
6.7.0.3
7.0.0
7.0.0.1
7.0.1
7.0.1.1
7.0.2
7.0.2.1
7.0.3
7.0.4
7.0.5
7.0.6
7.0.6.1
7.0.6.2
7.1.0
7.1.0.1
7.1.0.2
7.1.0.3
7.2.0
7.2.0.1
7.2.1
7.2.2
7.2.3
7.2.4
7.2.4.1
7.2.5
7.2.5.1
7.2.6
7.2.7
7.2.5.2
7.2.8
7.2.8.1
7.3.0
7.3.1
7.3.1.1
7.3.1.2
7.4.0
7.4.1
7.4.1.1
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 Previdian 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
A trusted third party reported exploitation.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the Previdian 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
- User-Agents
- Callback hosts
- 0
- 0
- 0
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
Scanner coverage
Nessus template detected 02 Jun 2025.
View Nessus template (opens in new tab)Virtual patch status
No Previdian 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
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS
15.9%
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
Timeline
From disclosure to observed exploitation
-
09:26 UTC
Nessus plugin available
Scanner coverage available
-
00:00 UTC
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
17:51 UTC
CVE published
Vulnerability disclosed publicly
-
15:08 UTC
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
Sample API response{
"cve_id": "CVE-2024-20481",
"confidence": "Confirmed",
"cvss_score": 5.8,
"cvss_estimated": false,
"epss_score": 0.15874,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}