Security readout for executives and security teams
Plain-English summary
This issue affects Windows systems using Cisco AnyConnect Secure Mobility Client with the Network Access Manager module. A local authenticated attacker who can configure a pre-logon script could cause code to run as SYSTEM, giving full control of that endpoint.
Executive priority
Treat as a moderate-priority endpoint hardening issue. It is not shown as actively exploited, but compromise can produce SYSTEM access on affected Windows devices.
Technical view
Cisco reports incorrect privilege assignment for scripts executed before user logon in the AnyConnect NAM module for Windows. Exploitation requires local access and high privileges, but successful exploitation permits arbitrary code execution with SYSTEM privileges. The provided sources do not identify specific affected or fixed versions.
Likely exposure
Exposure is limited to Windows endpoints running Cisco AnyConnect Secure Mobility Client with the NAM module, especially where pre-logon scripts are configured or administratively changeable.
Exploitation context
The source bundle does not show CISA KEV listing or any cited active exploitation. The attack is local, authenticated, and requires high privileges, reducing broad internet-scale risk but increasing post-compromise impact.
Researcher notes
Key uncertainty is version scope: the provided bundle lists the product but not affected or fixed versions. Validation should focus on Cisco advisory mapping, NAM presence, and whether pre-logon script configuration is reachable by local privileged users.
Mitigation direction
- Review Cisco advisory for affected and fixed AnyConnect NAM versions.
- Inventory Windows endpoints with AnyConnect Secure Mobility Client and NAM installed.
- Prioritize updates or configuration changes according to Cisco guidance.
- Restrict who can configure pre-logon scripts on managed endpoints.
- Monitor privileged local changes to AnyConnect NAM configuration.
Validation and detection
- Compare installed AnyConnect NAM versions against Cisco advisory guidance.
- Confirm whether pre-logon script execution is enabled on managed Windows endpoints.
- Review endpoint logs for unexpected SYSTEM-level execution tied to login workflows.
- Check management tooling for unauthorized changes to NAM script settings.
- Verify remediation status through endpoint inventory or software compliance reporting.
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
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CWE-266: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program 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-2021-40124 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
- 6.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/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:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H0.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.7MediumVector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20211103 Cisco AnyConnect Secure Mobility Client for Windows with Network Access Manager Module Privilege Escalation VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
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 Privilege Assignment
Incorrect Privilege Assignment represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.