CVE-2020-3529 json
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SSL VPN Direct Memory Access Denial of Service Vulnerability
published 2020-10-21 6 y ago modified 2026-08-11 2 mo ago also EUVD-2020-24800
- cvss
- 8.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.8%
- EPSS 1.8% chance of exploitation in 30 days, percentile 79%
- public exploits
- 0
- none known
Summary
A vulnerability in the SSL VPN negotiation process for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient direct memory access (DMA) memory management during the negotiation phase of an SSL VPN connection. An attacker could exploit this vulnerability by sending a steady stream of crafted Datagram TLS (DTLS) traffic to an affected device. A successful exploit could allow the attacker to exhaust DMA memory on the device and cause a DoS condition.
Patch / fix
- cisco adaptive_security_appliance 9.6.4.45
- cisco secure_firewall_threat_defense 6.3.0.6, 6.4.0.10, 6.5.0.5, 6.6.1
- cisco adaptive_security_appliance_software 9.8.4.29, 9.9.2.80, 9.10.1.44, 9.12.4.4, 9.13.1.13, 9.14.1.30
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
1.85% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Affected products
- Cisco Cisco Adaptive Security Appliance (ASA) Software
Classification
- Weakness
-
- CWE-400 Uncontrolled Resource Consumption
References
Sources
- CVE List CVE-2020-3529
- NVD CVE-2020-3529
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