Security readout for executives and security teams
Plain-English summary
This vulnerability lets an unauthenticated network attacker send reboot commands to the affected BMC firmware, disrupting availability of equipment managed by that controller. The known affected product is Lanner IAC-AST2500A standard firmware 1.10.0.
Executive priority
Treat this as a targeted availability risk for environments using the named Lanner BMC firmware. Prioritize exposed or operationally critical systems before routine patch cycles.
Technical view
CVE-2021-26733 is a broken access control issue in spx_restservice FirstReset_handler_func. The CVSS 3.1 vector is network-accessible, low complexity, no privileges, no user interaction, with low availability impact and no stated confidentiality or integrity impact.
Likely exposure
Exposure is most likely where Lanner IAC-AST2500A BMC management interfaces are reachable from untrusted networks or broad internal segments while running firmware 1.10.0.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. Risk is availability-focused: repeated or unauthorized BMC reboots could interrupt operations.
Researcher notes
Evidence identifies one affected firmware version and function. The CVSS vector indicates unauthenticated network reachability, but the provided sources do not name a patch level, workaround details, or exploitation in the wild.
Mitigation direction
- Identify any Lanner IAC-AST2500A systems running firmware 1.10.0.
- Check Lanner or Nozomi guidance for firmware updates or vendor-approved mitigations.
- Restrict BMC access to dedicated management networks or VPN-only administration.
- Block public internet exposure to affected BMC management services.
- Monitor for unexpected BMC reset or reboot activity.
Validation and detection
- Confirm product model and BMC firmware version from asset inventory.
- Validate the BMC management interface is not internet-accessible.
- Review network ACLs limiting BMC access to authorized administrators.
- Check BMC and infrastructure logs for unexplained reboot events.
- Document remediation status for each 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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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-2021-26733 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
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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:N/UI:N/S:U/C:N/I:N/A:L3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Source materials
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 Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.