CVE-2020-3373
No exploitation reported by the sources we read.
- Published2020-10-21
- WeaknessCWE-400 · CWE-401
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 IP fragment-handling implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak on an affected device. This memory leak could prevent traffic from being processed through the device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper error handling when specific failures occur during IP fragment reassembly. An attacker could exploit this vulnerability by sending crafted, fragmented IP traffic to a targeted device. A successful exploit could allow the attacker to continuously consume memory on the affected device and eventually impact traffic, resulting in a DoS condition. The device could require a manual reboot to recover from the DoS condition. Note: This vulnerability applies to both IP Version 4 (IPv4) and IP Version 6 (IPv6) traffic.
Timeline
dates in UTC- 2020-10-2119:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-3373?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-3373?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 |
|---|---|---|---|
| 9.8 | = 9.8.4.22 | no fix published | NVD |
| 9.8 | = 9.8.4.25 | no fix published | NVD |
| 9.12 | = 9.12.4.2 | no fix published | NVD |
| 9.12 | = 9.12.4.3 | no fix published | NVD |
| 9.13 | = 9.13.1.12 | no fix published | NVD |
| 9.14 | = 9.14.1.15 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.6 | = 6.6.0.1 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
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:C/C:N/I:N/A:H
- Published
- 2020-10-21
- Last Modified
- 2026-08-11
- NVD status
- Modified
Frequently asked questions
What is CVE-2020-3373?
Is CVE-2020-3373 actively exploited?
What is the CVSS score for CVE-2020-3373?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.