Cisco AnyConnect Secure Mobility Client for Windows with VPN Posture (HostScan) Module DLL Hijacking Vulnerability
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-427.
Summary
A vulnerability in the DLL loading mechanism of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client. This vulnerability is due to a race condition in the signature verification process for DLL files that are loaded on an affected device. An attacker could exploit this vulnerability by sending a series of crafted interprocess communication (IPC) messages to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected device with SYSTEM privileges. To exploit this vulnerability, the attacker must have valid credentials on the Windows system.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-1567
- 2026-10-03 Alias added: GHSA-wxfr-9v84-73vc
References
More Cisco Anyconnect Secure Mobility Client vulnerabilities
- TI-2020-02982 Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking Vulnerability KEVCVSS 3.1HIGH 7.8
- TI-2020-02715 Cisco AnyConnect Secure Mobility Client for Windows Uncontrolled Search Path Vulnerability KEVCVSS 3.1MEDIUM 6.5
- TI-2011-01789 The helper application in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect… CVSS 2.0HIGH 7.6
- TI-2011-01790 The helper application in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect… CVSS 2.0HIGH 9.3
- TI-2012-02179 The VPN downloader implementation in the WebLaunch feature in Cisco AnyConnect Secure… CVSS 2.0HIGH 9.3
- TI-2023-06884 Incorrect default permissions in Cisco Secure Client CVSS 3.1HIGH 7.8
Sources
- CVE-2021-1567 · CVE Program
- CVE-2021-1567 · NVD
- FIRST EPSS
- GHSA-wxfr-9v84-73vc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences