Security readout for executives and security teams
Plain-English summary
This vulnerability can let a remote attacker who already has high privileges crash the ASUS BMC web management service on affected server hardware. It is mainly an availability risk to out-of-band management, not a documented data theft or system takeover issue. Business urgency is moderate where affected BMC interfaces are reachable beyond a tightly controlled management segment.
Executive priority
Treat this as a moderate-priority infrastructure management risk. It does not indicate unauthenticated compromise or active exploitation, but disruption of BMC web management can impair incident response, remote recovery, and server operations. Prioritize internet-exposed or shared-network BMC interfaces first.
Technical view
CVE-2021-28198 is a CWE-120 buffer overflow in the Firmware protocol configuration function of ASUS BMC firmware web management. User-supplied string length is not verified. CVSS v3.1 is 4.9: network vector, low complexity, high privileges required, no user interaction, unchanged scope, and high availability impact only.
Likely exposure
Exposure is limited to the listed ASUS BMC firmware builds for ASMB9-iKVM and multiple ASUS server/workstation platforms. Systems without these BMC firmware versions are not shown as affected in the provided sources. Internet-reachable or broadly reachable BMC management interfaces increase operational risk.
Exploitation context
The source bundle does not show CISA KEV listing or evidence of active exploitation. The stated prerequisite is privileged permission, which reduces likelihood but means compromised admin credentials or over-broad management access could turn this into a BMC web-service denial-of-service event.
Researcher notes
Evidence identifies a length-validation flaw in firmware protocol configuration, requiring high privileges and producing availability impact. The provided sources do not name exploit availability, active exploitation, or specific fixed firmware versions. Avoid assuming broader ASUS BMC impact beyond the enumerated products and versions.
Mitigation direction
- Inventory ASUS BMC-managed servers and compare firmware versions against the affected list.
- Restrict BMC web management access to trusted management networks and administrator groups.
- Check ASUS and TWCERT guidance for vendor-approved firmware updates or workarounds.
- Review BMC account hygiene, MFA availability, and privileged access controls.
- Monitor BMC web service availability and administrative configuration changes.
Validation and detection
- Confirm affected product model and exact BMC firmware version from asset records or management console.
- Verify BMC web interfaces are not exposed to untrusted networks.
- Review logs for abnormal BMC web service termination or unexpected privileged configuration activity.
- Confirm remediation status against ASUS or TWCERT advisory information.
- Document compensating controls where firmware remediation is not yet confirmed.
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-2021-28198 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-132-4568-627f7-1.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.