Security readout for executives and security teams
Plain-English summary
This vulnerability affects specific ASUS BMC firmware versions used for server management. A privileged remote user can trigger a buffer overflow through the SMTP configuration page and crash the BMC web service. The known impact is availability loss, not data theft or system takeover, but BMC outages can disrupt server administration.
Executive priority
Treat this as a targeted availability risk for server management infrastructure. It is not currently supported as an emergency internet-wide exploitation issue, but affected BMCs should be found, access-restricted, and reviewed for vendor firmware guidance.
Technical view
CVE-2021-28189 is a CWE-120 buffer overflow in the ASUS BMC firmware SMTP configuration function. The web management page does not verify user-supplied string length. CVSS 3.1 is 4.9 with network access, low complexity, high privileges required, no user interaction, and high availability impact only.
Likely exposure
Exposure is limited to ASUS BMC firmware for Z10PR-D16 1.14.51, ASMB8-iKVM 1.14.51, and Z10PE-D16 WS 1.14.2. Risk is greatest where BMC web management is reachable by administrators over broad internal networks or remote management paths.
Exploitation context
The source bundle does not show CISA KEV listing or public active exploitation evidence. Exploitation requires privileged access to the BMC web interface. The cited impact is abnormal termination of the web service, consistent with denial of service rather than confirmed code execution.
Researcher notes
Evidence supports a length-validation flaw in the SMTP configuration function causing BMC web service termination. The bundle does not name a fixed version, patch procedure, proof of concept, or active exploitation. Avoid assuming broader ASUS product impact beyond the listed firmware and versions.
Mitigation direction
- Restrict BMC web access to dedicated management networks and trusted administrators.
- Review ASUS advisory and support channels for firmware guidance before changing production systems.
- Disable unnecessary remote paths to BMC management interfaces where operationally feasible.
- Monitor BMC web service availability and administrator activity for unexpected failures.
Validation and detection
- Inventory ASUS BMC models and firmware versions against the affected list.
- Confirm whether BMC web interfaces are reachable beyond the management network.
- Review administrative access controls for accounts with BMC web configuration privileges.
- Check logs or monitoring for unexpected BMC web service restarts or crashes.
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-2021-28189 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-132-4559-ad2b5-1.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.