Security readout for executives and security teams
Plain-English summary
CVE-2020-3306 is a denial-of-service flaw in Cisco ASA and Firepower Threat Defense DHCP handling. A remote unauthenticated attacker could disrupt an affected device by sending a crafted DHCP packet. The main business risk is loss of firewall or security gateway availability, not data theft.
Executive priority
Treat as a moderate availability risk for perimeter security infrastructure. Prioritize internet-edge or business-critical Cisco ASA and FTD devices, especially where outages would affect connectivity, VPN, or security enforcement.
Technical view
Cisco describes incorrect processing of certain DHCP packets in ASA and FTD software. The CVSS 3.0 score is 6.8 with network attack vector, no privileges, no user interaction, high attack complexity, changed scope, and high availability impact only. Exact affected versions are not included in the provided bundle.
Likely exposure
Exposure is most likely where Cisco ASA or FTD devices process DHCP traffic. The source bundle does not identify exact vulnerable versions or configurations, so validation requires checking Cisco’s advisory against deployed releases and DHCP roles.
Exploitation context
The provided data does not show CISA KEV listing or active exploitation. Cisco’s description says exploitation requires crafted DHCP packets and can cause DoS. Attack complexity is rated high, which reduces but does not remove operational risk.
Researcher notes
Evidence is limited to CVE metadata and Cisco’s advisory reference. The bundle does not include exact affected versions, fixed releases, workarounds, or exploit telemetry. Avoid claiming compromise risk beyond availability impact.
Mitigation direction
- Review Cisco’s advisory for affected and fixed release details.
- Upgrade ASA or FTD software if Cisco lists your release as vulnerable.
- Restrict DHCP packet exposure to trusted network paths where operationally feasible.
- Monitor affected devices for unexpected crashes, reloads, or availability loss.
- Do not rely on undocumented workarounds; confirm vendor guidance first.
Validation and detection
- Inventory Cisco ASA and FTD devices in scope.
- Identify devices that process DHCP traffic or relay related traffic.
- Compare running versions against the Cisco advisory.
- Review firewall uptime and crash logs for unexplained DoS symptoms.
- Confirm CVE-2020-3306 is not listed in CISA KEV in the provided data.
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-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-3306 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
- Medium
- CVSS
- 6.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/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:H/PR:N/UI:N/S:C/C:N/I:N/A:H2.24Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.8MediumVector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200506 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software DHCP 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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.