Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote attacker crash and reload an affected Cisco Firepower 1000 Series device running FTD Software by sending a crafted SSL/TLS message. The main business risk is loss of firewall/security gateway availability, not data theft.
Executive priority
Treat this as a high-priority availability issue for affected perimeter security devices. It can interrupt inspection or network access, so prioritize systems that protect production, remote access, or customer-facing environments.
Technical view
CVE-2020-3283 is an SSL/TLS handler vulnerability in Cisco FTD Software on Firepower 1000 Series. A communication error between internal functions can allow a crafted SSL/TLS message to cause a buffer underrun, crash, and device reload. CVSS 3.0 score is 8.6, with network attack vector and high availability impact.
Likely exposure
Exposure is likely limited to Cisco Firepower 1000 Series appliances running Cisco Firepower Threat Defense Software and reachable by SSL/TLS traffic. The source bundle does not identify exact affected versions, so teams must confirm applicability against Cisco guidance.
Exploitation context
The provided sources support unauthenticated remote denial of service via crafted SSL/TLS traffic. They do not support active exploitation claims; the bundle marks KEV as false and provides no public exploit-status evidence.
Researcher notes
Evidence is strongest for vulnerability class, impact, and affected platform. Exact affected versions and fixed releases are not included in the source bundle. Avoid assuming exploit activity or broader Cisco product impact without additional vendor evidence.
Mitigation direction
- Check Cisco’s advisory for affected and fixed release guidance.
- Prioritize remediation for internet-facing or critical-path Firepower 1000 devices.
- Apply Cisco-recommended software updates or workarounds where applicable.
- Ensure high-availability failover and monitoring are functioning.
- Limit unnecessary SSL/TLS exposure to affected devices where operationally feasible.
Validation and detection
- Inventory Firepower 1000 Series devices running FTD Software.
- Compare platform and software details against Cisco’s advisory.
- Review uptime and logs for unexplained reloads or crash events.
- Confirm perimeter devices have alerting for reload and availability loss.
- Document remediation status for each affected appliance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-119: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-3283 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200506 Cisco Firepower 1000 Series SSL/TLS Denial of Service VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.