CVE-2020-3436 json
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services File Upload Denial of Service Vulnerability
published 2020-10-21 6 y ago modified 2026-08-11 2 mo ago also EUVD-2020-24707
- cvss
- 8.6
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.9%
- EPSS 1.9% chance of exploitation in 30 days, percentile 80%
- public exploits
- 0
- none known
Summary
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to upload arbitrary-sized files to specific folders on an affected device, which could lead to an unexpected device reload. The vulnerability exists because the affected software does not efficiently handle the writing of large files to specific folders on the local file system. An attacker could exploit this vulnerability by uploading files to those specific folders. A successful exploit could allow the attacker to write a file that triggers a watchdog timeout, which would cause the device to unexpectedly reload, causing a denial of service (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
- cisco adaptive_security_appliance_software 9.8.4.25, 9.9.2.80, 9.10.1.44, 9.12.4.2, 9.13.1.12, 9.14.1.15
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
1.94% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 8.6 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVD | 3.1 | 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVD | 2.0 | 7.8 | AV:N/AC:L/Au:N/C:N/I:N/A:C |
Affected products
- Cisco Cisco Adaptive Security Appliance (ASA) Software
Classification
- Weakness
-
- CWE-434 Unrestricted Upload of File with Dangerous Type
References
Sources
- CVE List CVE-2020-3436
- NVD CVE-2020-3436
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