Cisco · Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) · Cisco ASA and FTD Denial-of-Service Vulnerability
Verdict
Patch first · actively exploited, reachable from the internet without credentials, and in the top 5% of CVEs by near-term exploitation probability
Added to CISA KEV 2024-10-24 · exploited in the wild for 703 days
CVSS 5.8 MEDIUM. The score is a summary; these three components are the part that decides whether something scanning the internet can use it.
| Attack vector | networkreachable over the network, with no local access needed |
|---|---|
| Privileges required | noneneeds no credentials at all |
| User interaction | nonecan be triggered with nobody interacting with the page or request |
| Base vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
| Weakness | CWE-772 |
This describes the vulnerability. It says nothing about whether your systems run it.
EPSS puts the probability of exploitation in the next 30 days at 0.1575, which places it in the top 5% of all tracked CVEs. The percentile is the more useful half: 0.18 in absolute terms sounds low until you know most of the internet-facing software in the world scores under that.
| EPSS probability | 0.1575 |
|---|---|
| Percentile | 0.968 — top 5% |
| Added to KEV | 2024-10-24 |
|---|---|
| Days exploited | 703 |
| Federal remediation due | not set |
| Ransomware use | no known ransomware campaign use |
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
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.