CVE-2024-20494
HIGHDescription
A vulnerability in the TLS cryptography functionality of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to improper data validation during the TLS 1.3 handshake. An attacker could exploit this vulnerability by sending a crafted TLS 1.3 packet to an affected system through a TLS 1.3-enabled listening socket. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: This vulnerability can also impact the integrity of a device by causing VPN HostScan communication failures or file transfer failures when Cisco ASA Software is upgraded using Cisco Adaptive Security Device Manager (ASDM).
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 42% of all known CVEs.
References
Related Vulnerabilities
Other CWE-1287 (Improper Validation of Specified Type of Input) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2024-4879 | Critical | 9.8 | 100% | KEV | - |
| CVE-2022-31007 | Medium | 4.9 | 27% | - | Fix |
| CVE-2024-6298 | Critical | 10.0 | 19% | - | - |
| CVE-2026-25639 | High | 7.5 | 2.7% | - | Fix |
| CVE-2021-43802 | Critical | 9.9 | 2.0% | - | Fix |
| CVE-2026-5946 | High | 7.5 | 1.9% | - | Fix |
Common questions
How do I fix CVE-2024-20494?
No published fix for CVE-2024-20494 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2024-20494 being actively exploited?
Not that we know of. CVE-2024-20494 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.51% is the estimated probability that it will be exploited in the next 30 days. That is higher than 42% of all scored CVEs.
How severe is CVE-2024-20494?
CVE-2024-20494 has a CVSS v3 base score of 8.6, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2024-20494
Markdown
[](https://tridentstack.com/cve/CVE-2024-20494)HTML
<a href="https://tridentstack.com/cve/CVE-2024-20494"><img src="https://tridentstack.com/cve/badge/CVE-2024-20494.svg" alt="CVE-2024-20494"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-11.