CVE-2020-3529
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.
EPSS 1.86% · 83.4th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| cisco | adaptive_security_appliance | 0, 0, 0 |
| cisco | firepower_threat_defense | 0, 6.4.0, 6.5.0 |
| cisco | adaptive_security_appliance_software | 9.9.0, 9.12.0, 9.13.0 |
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | n/a |
Exploit Intelligence
- CIRCL seen: CVE-2020-3529 (circl-sighting)
- 20201021 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SSL VPN Direct Memory Access Denial of Service Vulnerability (circl)
- https://services.google.com/fh/files/misc/m-trends-2025-en.pdf (vulncheck)
- (vulncheck-reported-exploitation)
- (vulncheck-reported-exploitation)
- (vulncheck-reported-exploitation)
Timeline
- Oct 21, 2020 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 23, 2021 EPSS Score
- Oct 26, 2021 EPSS Score
- Dec 27, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 28, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- May 1, 2022 EPSS Score
- Jul 3, 2022 EPSS Score
- Nov 6, 2022 EPSS Score
- Jan 8, 2023 EPSS Score
References
- 20201021 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SSL VPN Direct Memory Access Denial of Service Vulnerability vendor-advisory
- https://nvd.nist.gov/vuln/detail/CVE-2020-3529 advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-sbbyp-KqP6NgrE advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-inline-dos-nXqUyEqM advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-icmp-dos-hxxcycM advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dos-QFcNEPfx advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-frag-memleak-mCtqdP9n advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftdfmc-sft-mitm-tc8AzFs2 advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-dcrpt-dos-RYEkX4yy advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-fileup-dos-zvC7wtys advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-tcp-dos-N3DMnU4T advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-cacauthbyp-NCLGZm3Q advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snmp-dos-R8ENPbOs advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftdfmc-dirtrav-NW8XcuSB advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-container-esc-FmYqFBQV advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tcp-dos-GDcZDqAf advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxos-sbbp-XTuPkYTn advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fxosfcm-csrf-uhO4e5BZ advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospflls-37Xy2q6r advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-webdos-fBzM5Ynw advisory
…and 1 more