Security readout for executives and security teams
Plain-English summary
CVE-2021-1476 is a Cisco ASA and FTD command injection issue. It requires valid administrator-level credentials and local authenticated access, but successful exploitation could run operating system commands as root on the device. That makes it most serious where firewall administration is shared, weakly controlled, or already compromised.
Executive priority
Treat this as moderate priority unless firewall administrator credentials are weak, shared, or suspected compromised. Because root-level device compromise is possible after admin access, prioritize verification during network security appliance patch cycles.
Technical view
The CLI insufficiently validates user-supplied command input, enabling an authenticated local attacker with high privileges to execute arbitrary OS commands. CVSS 3.1 is 6.7 with local attack vector, low complexity, high privileges required, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to Cisco ASA and FTD environments where attackers can obtain administrator-level credentials and reach the device CLI locally or through permitted management access.
Exploitation context
The source bundle does not indicate known active exploitation, and CISA KEV status is false. Exploitation requires valid administrator-level credentials, so this is mainly a post-compromise, insider, or credential-misuse risk.
Researcher notes
Evidence supports command injection in Cisco ASA and FTD CLI with CWE-78 classification and root-level OS command impact. The provided data does not include affected version ranges, proof of exploitation, or specific fixed releases; use Cisco's advisory for those details.
Mitigation direction
- Check Cisco's advisory for affected releases, fixed software, and any stated workarounds.
- Restrict administrator-level device access to trusted management networks and named administrators.
- Audit local administrator accounts and remove unnecessary or stale credentials.
- Monitor administrative CLI activity for unusual command attempts.
Validation and detection
- Inventory Cisco ASA and FTD devices and record software versions.
- Compare versions against Cisco's advisory for CVE-2021-1476.
- Review administrator account lists for excessive or stale access.
- Check device management logs for unexpected CLI usage.
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-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter telemetry. 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 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-2021-1476 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
- 20210428 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Command Injection 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 Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.