Security readout for executives and security teams
Plain-English summary
This issue affects ASUS BMC firmware web management on specific server and workstation platforms. A privileged remote user can enter overly long Active Directory configuration data and crash the BMC web service, disrupting management access. The available sources describe availability impact, not data theft or code execution.
Executive priority
Treat this as a moderate infrastructure availability risk. Prioritize internet- or broadly reachable BMC interfaces and systems supporting critical services. The urgency is lower than unauthenticated remote compromise, but BMC outages can impair operations and recovery.
Technical view
CVE-2021-28197 is a CWE-120 buffer overflow in the Active Directory configuration function of ASUS BMC firmware. The function does not validate user-supplied string length. CVSS v3.1 is 4.9: network-accessible, low complexity, high privileges required, no user interaction, and high availability impact only.
Likely exposure
Exposure is likely limited to organizations running the listed ASUS BMC firmware versions on ASMB9-iKVM, RS, ESC, E700, WS, Z11PA, or KNPA platforms, especially where BMC web management is reachable by privileged administrators over a network.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The described attacker needs privileged permission, which materially reduces likelihood, but BMC interfaces are operationally sensitive because losing web management can affect server administration and incident response.
Researcher notes
Evidence supports a privileged, remote availability impact via unchecked string length in Active Directory configuration. The bundle does not provide exploit details, proof of active exploitation, or a specific fixed firmware version. Validate only with non-destructive configuration and log review methods.
Mitigation direction
- Check ASUS Product Security Advisory for model-specific firmware guidance.
- Contact ASUS support or TWCERT if the applicable fixed version is unclear.
- Restrict BMC web management access to trusted administrative networks only.
- Limit privileged BMC accounts to required administrators.
- Monitor BMC web service crashes until remediation is confirmed.
Validation and detection
- Inventory ASUS BMC models and firmware versions against the affected list.
- Confirm whether BMC web management is reachable from untrusted networks.
- Review privileged BMC account assignments and recent access activity.
- Check logs or monitoring for abnormal BMC web service termination.
- Document vendor firmware guidance and remediation status per affected asset.
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
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCVE-2021-28197 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-132-4567-34350-1.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.