Security readout for executives and security teams
Plain-English summary
This flaw lets someone who already has administrator access to affected Cisco small business wireless access points run operating-system commands as root through the web management interface. It is not a drive-by internet bug, but it can turn stolen or misused admin credentials into full device control.
Executive priority
Treat this as a targeted infrastructure hardening item, not an emergency without additional evidence. Prioritize internet-reachable or broadly reachable management interfaces and environments with weak administrative credential controls.
Technical view
CVE-2021-1553 is a CWE-77 command injection issue in the web-based management interface of certain Cisco Small Business 100, 300, and 500 Series Wireless Access Points. Improper validation of user input allows crafted HTTP requests by an authenticated remote administrator to execute arbitrary commands with root privileges.
Likely exposure
Exposure is likely limited to organizations running affected Cisco Small Business 100, 300, or 500 Series wireless access points, especially where the management interface is reachable over the network. Risk depends heavily on who has administrative credentials and whether those credentials are protected.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. Exploitation requires valid administrative credentials and remote access to the web management interface. Successful exploitation provides root-level command execution on the device.
Researcher notes
The key constraint is PR:H: an attacker needs valid administrative credentials. The impact is still meaningful because successful exploitation runs arbitrary commands as root on network infrastructure. The provided sources do not include exploit code, active exploitation evidence, or specific fixed version details.
Mitigation direction
- Review Cisco's advisory for affected models, fixed releases, and supported remediation guidance.
- Restrict access to the web management interface to trusted administrative networks only.
- Audit administrative accounts and remove unused, shared, or weak credentials.
- Rotate administrator passwords if credential exposure is suspected.
- Monitor affected access points for unexpected configuration or command activity.
Validation and detection
- Inventory Cisco Small Business 100, 300, and 500 Series wireless access points.
- Confirm whether each device runs software covered by Cisco's advisory.
- Verify the management interface is not exposed to untrusted networks.
- Review admin account lists for stale, shared, or excessive privileges.
- Check logs for unusual authenticated management 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-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-2021-1553 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
- 4.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
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:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L1.23.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.7MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- 20210519 Cisco Small Business 100, 300, and 500 Series Wireless Access Points Command Injection VulnerabilitiesCVE 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.