Security readout for executives and security teams
Plain-English summary
LogonExpert 8.1 has a Windows service configuration flaw. Because the service path is not quoted and runs as LocalSystem, a local low-privileged user may be able to gain full system-level control when the service starts. This is mainly a workstation or server hardening issue where LogonExpert is installed.
Executive priority
Treat as high priority where LogonExpert 8.1 is deployed. It does not enable remote break-in by itself, but it can turn a minor local compromise into full system control. Prioritize systems with multiple users or remote access exposure.
Technical view
CVE-2021-47890 is CWE-428: an unquoted service path in Softros Systems LogonExpert 8.1, affecting the LogonExpertSvc service. The service runs with LocalSystem privileges. CVSS v4.0 is 8.5, with local attack vector, low complexity, low privileges required, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to Windows systems running Softros LogonExpert 8.1 with the vulnerable LogonExpertSvc service configuration. The attacker needs local access or an existing low-privileged foothold on the host.
Exploitation context
The CVE is not marked in CISA KEV in the provided data. A public ExploitDB reference is listed, but the sources do not establish active exploitation in the wild. This vulnerability is useful for privilege escalation after initial access.
Researcher notes
Evidence supports LogonExpert 8.1 only. The provided sources do not identify a vendor patch level, affected CPE, or active exploitation. Validate exposure by service configuration, service privilege, version, and filesystem permissions. Avoid assuming other LogonExpert versions are affected without vendor confirmation.
Mitigation direction
- Identify all systems running LogonExpert 8.1.
- Check Softros guidance for a fixed version or supported remediation.
- Restrict write access to directories in the service path hierarchy.
- If vendor-approved, correct the service path quoting configuration.
- Prioritize remediation on shared, remote-access, and administrator-used systems.
Validation and detection
- Inventory installed LogonExpert versions across endpoints and servers.
- Confirm whether LogonExpertSvc exists on each system.
- Review whether the service path is unquoted.
- Verify the service runs as LocalSystem.
- Check directory permissions along the service path for low-privileged write access.
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-428: 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-2021-47890 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
- 8.5 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
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:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.5HighVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-49586CVE reference · exploit
- Vendor HomepageCVE reference · product
- Software Download LinkCVE reference · product
- VulnCheck Advisory: LogonExpert 8.1 - 'LogonExpertSvc' Unquoted Service PathCVE reference · third-party-advisory
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.
Unquoted Search Path or Element
Unquoted Search Path or Element represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.