Security readout for executives and security teams
Plain-English summary
This vulnerability can let a local, already authenticated attacker raise privileges to Windows NT SYSTEM on Advantech WISE-PaaS/OTA Server 3.0.9. That level of access can allow full control of the affected host. The sources do not show active exploitation or a named patch.
Executive priority
Treat this as high priority where the product is present. It is not internet-remote, but successful exploitation could give full host control and undermine operational systems using WISE-PaaS/OTA.
Technical view
CVE-2021-40397 is a CWE-276 incorrect-permissions issue in the installation of Advantech WISE-PaaS/OTA Server 3.0.9. A low-privileged local attacker may replace a specially crafted file and escalate privileges to NT SYSTEM. CVSS 3.0 score is 8.8.
Likely exposure
Exposure appears limited to systems running Advantech WISE-PaaS/OTA Server 3.0.9, especially where low-privileged local users can access the host. The CVE affected-product metadata is incomplete, so inventory confirmation is important.
Exploitation context
The vulnerability requires local access and low privileges, with no user interaction. The provided sources do not report known exploitation, and the bundle marks it as not in KEV.
Researcher notes
The key evidence is Talos TALOS-2021-1409 and the CVE record. Public metadata names version 3.0.9, CWE-276, AV:L/PR:L/UI:N, and NT SYSTEM escalation. Affected CPE data is absent, so scope depends on internal inventory.
Mitigation direction
- Identify any WISE-PaaS/OTA Server 3.0.9 installations.
- Check Advantech and Talos guidance for supported fixes or upgrade paths.
- Restrict local user access to affected servers.
- Review installation and application file permissions for unsafe write access.
- Prioritize remediation on shared or remotely administered Windows hosts.
Validation and detection
- Confirm whether WISE-PaaS/OTA Server 3.0.9 is installed.
- Verify the host is not exposed to unnecessary local users.
- Review file permissions around installation-controlled paths.
- Check vulnerability management tools for CVE-2021-40397 coverage.
- Document any compensating controls if no vendor fix is available.
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-276: 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 lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40397 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
- High
- CVSS
- 8.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H26Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.8HighVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1409CVE 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.
Incorrect Default Permissions
Incorrect Default Permissions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.