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TI-2021-00964 Aliases CVE-2021-1237GHSA-656q-3mvc-v648

Cisco AnyConnect Secure Mobility Client for Windows DLL Injection Vulnerability

Priority LOW 36CWE-427Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
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 Network Access Manager and Web Security Agent components of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL injection attack. To exploit this vulnerability, the attacker would need to have valid credentials on the Windows system. The vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by inserting a configuration file in a specific path in the system which, in turn, causes a malicious DLL file to be loaded when the application starts. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00412 35th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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

VendorProductAffected versionsFixed inStatusSource
CiscoCisco AnyConnect Secure Mobility Clientall versions—No fix listedCNA
  • Cisco AnyConnect Secure Mobility Client VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:cisco:anyconnect_secure_mobility_client:*:*:*:*:*:windows:*:*before 4.9.04043VulnerableCisco
  • cpe:2.3:a:cisco:anyconnect_secure_mobility_client:*:*:*:*:*:windows:*:* Versions before 4.9.04043 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-1237
  2. 2026-10-03 Alias added: GHSA-656q-3mvc-v648

References

Advisory 1

  • 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
See all 68 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences