Security readout for executives and security teams
Plain-English summary
This flaw lets an unauthenticated network attacker terminate other users' active sessions on affected Lanner BMC firmware, creating a denial-of-service condition. The public sources identify only Lanner IAC-AST2500A standard firmware 1.10.0 as affected. It is disruptive rather than data-stealing, but exposed management interfaces can create operational impact.
Executive priority
Handle this as a moderate operational availability risk. It is not described as data theft or system takeover, but it can disrupt management access to affected devices. Prioritize if affected BMCs support critical OT, IoT, or security infrastructure, or if management interfaces are broadly reachable.
Technical view
CVE-2021-44467 is broken access control in the KillDupUsr_func function of spx_restservice. With a correctly guessed input parameter, an attacker can terminate active sessions belonging to other users. CVSS 3.1 is 5.3, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L, mapped to CWE-284.
Likely exposure
Exposure is limited to environments running Lanner IAC-AST2500A standard firmware version 1.10.0, especially where the BMC or spx_restservice is reachable over a network. The provided data marks other versions as unaffected by default, but does not prove broader fleet status.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is remotely reachable and requires no privileges or user interaction, but the attacker must correctly guess an input parameter. Public sources describe denial of service through session termination, not code execution.
Researcher notes
Evidence is specific but incomplete on remediation. Sources identify the vulnerable function, impact, affected product and version, CVSS vector, and CWE. They do not provide evidence of active exploitation in this bundle, and no concrete patch version or workaround is named here.
Mitigation direction
- Inventory Lanner IAC-AST2500A devices and identify firmware version 1.10.0.
- Check Lanner or Nozomi guidance for fixed firmware or supported mitigation.
- Restrict BMC management access to trusted administrative networks only.
- Monitor for unexplained administrator session drops on affected devices.
- Prioritize exposed or operationally critical devices for remediation.
Validation and detection
- Confirm whether any Lanner IAC-AST2500A devices run standard firmware 1.10.0.
- Review network paths to BMC or spx_restservice management interfaces.
- Check logs for repeated unexpected session termination events.
- Verify only authorized administrators can reach management services.
- Track vendor advisory status before declaring remediation complete.
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-2021-44467 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.