Security readout for executives and security teams
Plain-English summary
This vulnerability affects specific ASUS BMC firmware web management pages. An authenticated administrator could abuse a file deletion feature to traverse paths and read system files. The business risk is mainly sensitive information exposure from management controllers, not unauthenticated takeover or service outage based on the supplied sources.
Executive priority
Treat as a controlled but important infrastructure risk. Prioritize systems where BMC interfaces are reachable from broad networks or where administrator credentials may be shared, stale, or exposed. The issue is not documented here as actively exploited, but BMCs can expose sensitive host-management data.
Technical view
CVE-2021-28209 is CWE-22 path traversal in the ASUS BMC firmware Delete video file function. The vulnerable parameter is not filtered. CVSS 3.1 is 4.9: network reachable, low complexity, high privileges required, no user interaction, high confidentiality impact, no integrity or availability impact.
Likely exposure
Exposure is limited to organizations running the listed ASUS BMC firmware versions, including ASMB9-iKVM 1.11.12 and multiple RS, ESC, E700, WS, Z11PA, and KNPA models. Risk increases if BMC web management is reachable beyond a tightly controlled administration network.
Exploitation context
The source bundle does not show CISA KEV listing, public active exploitation, or exploit availability. The CVSS vector requires administrator privileges, so this is most relevant after credential compromise, insider misuse, or excessive administrative access to BMC management pages.
Researcher notes
Evidence is limited to the CVE description, CVSS vector, affected firmware list, and references. Do not assume unauthenticated exploitation or integrity impact. Validation should focus on affected firmware presence, BMC reachability, administrator access paths, and vendor-published firmware or mitigation status.
Mitigation direction
- Check ASUS security advisory and support channels for firmware updates or vendor mitigations.
- Restrict BMC web management access to trusted administration networks only.
- Review and reduce BMC administrator accounts to the minimum required set.
- Rotate or reset BMC administrator credentials if compromise is suspected.
- Monitor BMC administrative activity for unusual file access or video-delete actions.
Validation and detection
- Inventory ASUS systems and match BMC firmware versions against the affected list.
- Confirm whether BMC web management is externally reachable or broadly reachable internally.
- Verify which users have administrator permission on affected BMC interfaces.
- Check ASUS guidance for patched firmware applicability to each affected model.
- Review available BMC logs for unexpected administrative file-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-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-28209 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
- 4.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
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:H/I:N/A:N1.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.9MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.asus.com/content/ASUS-Product-Security-Advisory/CVE reference · x_refsource_MISC
- https://www.asus.com/tw/support/callus/CVE reference · x_refsource_MISC
- https://www.twcert.org.tw/tw/cp-132-4579-c8827-1.htmlCVE reference · x_refsource_MISC
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 Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.