CVE-2020-3555
No exploitation reported by the sources we read.
- Published2020-10-21
- Fixed in9.14.1.19 · 9.13.1.13 · 9.12.4.2 · 9.10.1.43 · 9.9.2.80 · 9.8.4.24
- WeaknessCWE-404
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
A vulnerability in the SIP inspection process of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a watchdog timeout and crash during the cleanup of threads that are associated with a SIP connection that is being deleted from the connection list. An attacker could exploit this vulnerability by sending a high rate of crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a watchdog timeout and crash, resulting in a crash and reload of the affected device.
Timeline
dates in UTC- 2020-10-2119:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-3555?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-3555?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.14 | ≥ 9.14.0, < 9.14.1.19 | 9.14.1.19 | NVD |
| 9.13 | ≥ 9.13.0, < 9.13.1.13 | 9.13.1.13 | NVD |
| 9.12 | ≥ 9.12.0, < 9.12.4.2 | 9.12.4.2 | NVD |
| 9.10 | ≥ 9.10.0, < 9.10.1.43 | 9.10.1.43 | NVD |
| 9.9 | ≥ 9.9.0, < 9.9.2.80 | 9.9.2.80 | NVD |
| 9.x | ≥ 9.7.0, < 9.8.4.24 | 9.8.4.24 | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.5 | ≥ 6.5.0, < 6.5.0.5 | 6.5.0.5 | NVD |
| 6.4 | ≥ 6.4.0, < 6.4.0.10 | 6.4.0.10 | NVD |
| 6.3 | ≥ 6.3.0, < 6.3.0.6 | 6.3.0.6 | NVD |
| 6.2 | ≤ 6.2.2 | no fix published | NVD |
| 6.6 | = 6.6.0 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.6 | < 9.6.4.43 | 9.6.4.43 | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Cisco ASA to 9.14.1.19 · 9.13.1.13 · 9.12.4.2 · 9.10.1.43 · 9.9.2.80 · 9.8.4.24
Advisories and patches
- tools.cisco.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2020-10-21
- Last Modified
- 2026-08-11
- NVD status
- Modified
Frequently asked questions
What is CVE-2020-3555?
Is CVE-2020-3555 actively exploited?
What is the CVSS score for CVE-2020-3555?
Hear about the next vulnerability in your software
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
No credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.