Security readout for executives and security teams
Plain-English summary
This issue lets a trusted Cisco Firepower Threat Defense administrator break out of intended CLI controls and run operating system commands as root. It is not a remote unauthenticated bug, but it can turn an already privileged account into full device compromise.
Executive priority
Prioritize remediation during the next security maintenance window, sooner for internet-edge or high-trust firewall deployments. The business risk is post-authentication device takeover by a privileged user or compromised admin account.
Technical view
Cisco FTD Software has insufficient validation of user-supplied CLI command arguments. An authenticated local attacker with administrative privileges can submit crafted input to affected commands and execute arbitrary commands as root on the underlying operating system. Cisco released software updates; the advisory states there are no workarounds.
Likely exposure
Exposure is limited to Cisco Firepower Threat Defense Software deployments matching the cited affected versions, including 6.2.3, 6.6.0.1, and 6.4.0.6, where administrative CLI access is available.
Exploitation context
The provided sources do not show active exploitation, and CISA KEV status is false. Exploitation requires authenticated local administrative access, but successful exploitation gives root-level control of the affected device.
Researcher notes
This is CWE-20 input validation with CVSS 3.1 score 6.7: AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. The source bundle does not identify specific affected CLI commands or public exploit details.
Mitigation direction
- Apply Cisco software updates identified in the vendor advisory.
- Do not rely on workarounds; Cisco states none address this vulnerability.
- Restrict administrative CLI access to trusted management paths and users.
- Review Cisco guidance for exact fixed releases and upgrade planning.
Validation and detection
- Inventory Cisco FTD Software versions across managed devices.
- Confirm affected releases against Cisco advisory coverage.
- Verify updated software is installed after maintenance.
- Review administrative account access for unnecessary CLI privileges.
- Monitor privileged administrative activity on FTD devices.
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
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-34752 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 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/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:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H0.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.7MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- cisco-sa-ftd-cmdinject-FmzsLN8CVE reference
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 Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.