Security readout for executives and security teams
Plain-English summary
This flaw can make certain Cisco Firepower 2100 security appliances restart if an attacker on the same adjacent network reaches the management interface with crafted ARP traffic. The business impact is availability: firewall/security services may be interrupted while the device reloads. The source bundle does not show data theft or remote internet exploitation.
Executive priority
Prioritize remediation for Firepower 2100 devices protecting critical network paths or reachable from shared management networks. Treat as high availability risk, not confirmed compromise risk.
Technical view
CVE-2020-3334 affects ARP packet processing in Cisco ASA Software and Cisco FTD Software on Cisco Firepower 2100 Series appliances. An unauthenticated adjacent attacker can send unicast ARP packets that reach the management interface, consume resources, disrupt internal keepalives, and eventually trigger a device reload, causing DoS.
Likely exposure
Exposure is most likely where Firepower 2100 management interfaces are reachable from untrusted or broadly accessible Layer 2 networks. Internet-only scanning is less relevant because the CVSS attack vector is adjacent, not network-wide remote.
Exploitation context
The provided sources do not state active exploitation, and KEV is false. Exploitation requires adjacent network access to traffic that reaches the management interface and targets availability rather than confidentiality or integrity.
Researcher notes
The prompt lacks exact affected and fixed version ranges. Validation should anchor on Cisco’s advisory and local inventory. Do not infer broader Cisco product exposure beyond Firepower 2100 ASA/FTD context in the sources.
Mitigation direction
- Review Cisco advisory for affected releases and Cisco-recommended fixed software.
- Apply vendor-recommended updates where the deployed release is affected.
- Restrict management-interface adjacency to trusted administrative networks where feasible.
- Monitor for unexpected reloads and abnormal ARP activity near management interfaces.
Validation and detection
- Inventory Cisco Firepower 2100 appliances and their ASA or FTD software versions.
- Compare deployed versions against the Cisco advisory’s affected and fixed release guidance.
- Verify management interfaces are not exposed to untrusted adjacent segments.
- Review device logs for reload events consistent with management-plane resource exhaustion.
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
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ATT&CK lookup starting points
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CWE-399: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-3334 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:A/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:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.4HighVector: CVSS:3.0/AV:A/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 2100 Series Security Appliances ARP 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.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.