Security readout for executives and security teams
Plain-English summary
This flaw lets a logged-in Cisco SD-WAN administrator abuse specific CLI commands to run operating-system commands as root. It is not described as remotely exploitable by an unauthenticated attacker, but compromise or misuse of an admin account could lead to full device control.
Executive priority
Treat this as a controlled but serious infrastructure risk. Prioritize validation and vendor-guided remediation for Cisco SD-WAN devices, especially where many administrators or shared admin accounts exist.
Technical view
CVE-2021-34726 is a CWE-77 command injection issue in Cisco SD-WAN Software CLI input validation. Exploitation requires local access, low attack complexity, no user interaction, and high privileges. Successful exploitation can impact confidentiality, integrity, and availability with root-level command execution.
Likely exposure
Exposure is most likely in environments running Cisco SD-WAN Software where administrative users can access the device CLI. The source bundle does not provide specific affected or fixed versions, so teams must verify against Cisco’s advisory.
Exploitation context
The source bundle says exploitation requires authentication as an administrative user and crafted CLI input. It is not listed as CISA KEV, and no provided source states active exploitation in the wild.
Researcher notes
The key constraint is PR:H and AV:L, which lowers broad internet-exploitation risk but raises post-compromise impact. The public bundle lacks affected-version detail, exploit evidence, and fixed-release information beyond the vendor advisory reference.
Mitigation direction
- Review the Cisco advisory to identify affected releases and fixed upgrade targets.
- Limit administrative CLI access to trusted administrators and management networks.
- Audit and remove unnecessary administrative accounts on SD-WAN devices.
- Monitor Cisco guidance for any additional mitigations or fixed-version changes.
Validation and detection
- Inventory Cisco SD-WAN devices and record installed software versions.
- Compare versions and product names with the Cisco advisory.
- Review administrative CLI access controls and account assignments.
- Check administrative activity logs for unexpected CLI use.
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-77: 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-2021-34726 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
- 20210922 Cisco SD-WAN 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 a Command ('Command Injection')
Improper Neutralization of Special Elements used in a Command ('Command Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.