Security readout for executives and security teams
Plain-English summary
This vulnerability lets a highly privileged local user on Cisco Firepower Threat Defense bypass disabled expert mode and obtain root-level command access through the support tunnel feature. It is serious for appliance integrity, but the attacker must already have authenticated local access with high privileges.
Executive priority
Treat as a controlled but important firewall-platform risk. Prioritize validation on production FTD appliances, especially where many administrators have access or admin credentials may be exposed.
Technical view
CVE-2020-3253 is an improper access control issue in Cisco FTD support tunnel configuration. With local access and high privileges, an authenticated attacker could reach the device shell despite expert mode being disabled and run system commands as root.
Likely exposure
Exposure is limited to Cisco Firepower Threat Defense Software. The provided sources do not identify specific affected versions, so teams must compare deployed FTD versions against Cisco’s advisory.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle. No provided source states active exploitation. Practical abuse requires authenticated local access with high privileges, reducing broad remote risk but increasing concern for insider or compromised-admin scenarios.
Researcher notes
Impact is high after prerequisite access: root command execution on the affected device. The main uncertainty is version scope because the supplied CVE bundle lists affected versions as n/a and defers detail to Cisco’s advisory.
Mitigation direction
- Review Cisco’s advisory for affected and fixed FTD release guidance.
- Upgrade affected Cisco Firepower Threat Defense deployments per vendor direction.
- Restrict local and administrative access to trusted operators only.
- Audit support tunnel use and disable unnecessary operational access paths.
Validation and detection
- Inventory all Cisco Firepower Threat Defense deployments and versions.
- Compare deployed versions against Cisco’s advisory.
- Review administrative accounts for unnecessary local or high-privilege access.
- Check logs for unexpected support tunnel configuration or shell activity.
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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-3253 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
- 6.7 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H0.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.7MediumVector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200506 Cisco Firepower Threat Defense Software Shell Access 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 Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.