Security readout for executives and security teams
Plain-English summary
This flaw affects ASUS server BMC firmware web management. A highly privileged remote user can trigger a buffer overflow in the user modification function and crash the BMC web service. The business risk is disruption to out-of-band management, not confirmed data theft or system compromise.
Executive priority
Treat as a moderate availability risk for server management infrastructure. Prioritize systems where BMC access supports production recovery, remote operations, or high-value hardware, especially if administrative access is broadly shared.
Technical view
CVE-2021-28199 is a CWE-120 buffer overflow in the Modify user's information function of ASUS BMC firmware. The function does not validate user-supplied string length. CVSS 3.1 is 4.9: network reachable, low complexity, high privileges required, no confidentiality or integrity impact, high availability impact.
Likely exposure
Exposure is limited to listed ASUS BMC firmware versions on ASMB9-iKVM and specific ASUS server or workstation platforms. The public record indicates the vulnerable function is in the BMC web management page and requires privileged access.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. Reported impact is abnormal termination of the web service after a privileged remote attacker abuses the length validation flaw.
Researcher notes
Evidence supports a length validation failure causing buffer overflow and web service termination. The provided sources do not claim code execution, data exposure, integrity impact, public exploit availability, or a named fixed version.
Mitigation direction
- Inventory ASUS BMC firmware versions against the affected product list.
- Check ASUS and TWCERT advisories for fixed firmware or official mitigation guidance.
- Limit BMC web management access to trusted administrative networks.
- Review privileged BMC accounts and remove unnecessary access.
- Monitor BMC web service availability and unexpected restarts.
Validation and detection
- Confirm whether any listed ASUS models and firmware versions are deployed.
- Verify BMC web management is not reachable from untrusted networks.
- Review BMC account roles for high-privilege users.
- Check vendor advisory pages for model-specific firmware remediation status.
- Correlate BMC web service crashes with administrative activity logs.
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-120: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-28199 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:N/I:N/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:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H1.23.6Primary 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:N/I:N/A:H
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-132-4569-6b391-1.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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.