CVE-2021-1237

SYSTEM code execution via DLL injection

Published Jan 13, 2021 · Updated Nov 12, 2024

DLL injection in Cisco AnyConnect Secure Mobility Client for Windows before 4.9.04043 allows local users to execute arbitrary code via crafted configuration files. The Network Access Manager and Web Security Agent load runtime resources without sufficient validation, allowing a configuration file in a specific path to cause a malicious DLL to load when the client starts. Valid Windows credentials and local access are required, and successful exploitation runs code with SYSTEM privileges.

CVSS severity7.8
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

DLL injection in Cisco AnyConnect Secure Mobility Client for Windows before 4.9.04043 allows local users to execute arbitrary code via crafted configuration files. The Network Access Manager and Web Security Agent load runtime resources without sufficient validation, allowing a configuration file in a specific path to cause a malicious DLL to load when the client starts. Valid Windows credentials and local access are required, and successful exploitation runs code with SYSTEM privileges.

The record

CVE
CVE-2021-1237
Published
Jan 13, 2021
Updated
Nov 12, 2024
Vendor
ClamAV
Product
Cisco Secure Client
Classifications
CWE-427, T1574.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

ClamAV · Cisco Secure Clientversion=n/a

Published CVSS scores

7.8Cisco Systems, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2National Institute of Standards and TechnologyAV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-427Uncontrolled Search Path Element
T1574.002DLL Side-Loading

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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