# CVE-2021-1237: Cisco AnyConnect Secure Mobility Client for Windows DLL Injection Vulnerability

> Local authenticated attackers can execute arbitrary code with SYSTEM privileges via DLL injection in Cisco AnyConnect Secure Mobility Client for Windows.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Jan 2021
- **Updated:** 12 Nov 2024
- **Also known as:** GHSA-656q-3mvc-v648

## What is CVE-2021-1237?

CVE-2021-1237 is a high-severity code injection vulnerability in Cisco Anyconnect Secure Mobility Client, published on 13 Jan 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2021-1237?

It affects 1 product.


Products: Cisco Anyconnect Secure Mobility Client.

## How do I fix CVE-2021-1237?

No fix has been published for CVE-2021-1237 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1237 being exploited?

There is no known exploitation of CVE-2021-1237 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Anyconnect Secure Mobility Client

- [CVE-2020-3433](https://insights.sbomify.com/CVE-2020-3433/): Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking (high 7.8, exploited in the wild)
- [CVE-2020-3153](https://insights.sbomify.com/CVE-2020-3153/): Cisco AnyConnect Secure Mobility Client for Windows Uncontrolled Search Path (medium 6.5, exploited in the wild)
- [CVE-2012-3088](https://insights.sbomify.com/CVE-2012-3088/): Security feature bypass in n/a (critical 9.3)
- [CVE-2012-2493](https://insights.sbomify.com/CVE-2012-2493/): Code injection in n/a (critical 9.3)
- [CVE-2011-2040](https://insights.sbomify.com/CVE-2011-2040/): Code injection in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1237 and fix it if it is affected.

What it is: CVE-2021-1237 is a high-severity code injection vulnerability in Cisco Anyconnect Secure Mobility Client, published on 13 Jan 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-1237 in the wild and no public exploit code.

Affected product: Cisco Anyconnect Secure Mobility Client. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-1237/ (Markdown: https://insights.sbomify.com/CVE-2021-1237/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1237
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1237
- OSV: https://osv.dev/vulnerability/CVE-2021-1237

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-1237/
Summaries are generated and may contain mistakes; the official description above is the record.