CVE-2020-3433 Cisco CVE debrief

Who should care

Organizations that deploy Cisco AnyConnect Secure Mobility Client for Windows, especially security, endpoint, and IT teams responsible for remote access software on managed Windows systems.

Technical summary

The issue is categorized as DLL hijacking in the Windows client. In practical terms, that means the application may load a DLL from an unintended location, which can let an attacker influence what code the process loads. Because the vulnerable software is a remote access client on Windows, endpoints running the client should be reviewed and updated promptly.

Defensive priority

High. CISA has placed this CVE in the KEV catalog, and the supplied metadata marks it as associated with known ransomware campaign use. Prioritize remediation on all exposed and business-critical Windows endpoints running the affected client.

Recommended defensive actions

• Inventory all Windows systems running Cisco AnyConnect Secure Mobility Client and identify affected versions.
• Apply Cisco updates per the vendor instructions referenced in the CISA KEV entry.
• Prioritize remediation on high-value, frequently used, or hard-to-monitor endpoints.
• Validate that remediation is complete by checking versions after patching and documenting exceptions.
• Use endpoint controls such as application allowlisting and EDR detections to spot unexpected DLL loading behavior on AnyConnect hosts.

Evidence notes

Evidence is limited to the supplied CISA KEV metadata, the CVE record title/description, and the official record links. The KEV metadata explicitly identifies the vulnerability as 'Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability,' marks it as known exploited, assigns a due date of 2022-11-14, and states 'Apply updates per vendor instructions.' The KEV notes also reference Cisco's security advisory and the NVD entry, but no additional advisory text was supplied here.

Official resources