# CVE-2021-1398: Cisco IOS XE Software Arbitrary Code Execution Vulnerability

> An attacker with local access or physical presence can execute arbitrary code on Cisco IOS XE devices by tampering with boot files, potentially bypassing secure boot.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Mar 2021
- **Updated:** 8 Nov 2024
- **Also known as:** GHSA-57gp-qx9r-6m7m

## What is CVE-2021-1398?

CVE-2021-1398 is a medium-severity code injection vulnerability in Cisco Ios Xe, published on 24 Mar 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 boot logic of Cisco IOS XE Software could allow an authenticated, local attacker with level 15 privileges or an unauthenticated attacker with physical access to execute arbitrary code on the underlying Linux operating system of an affected device. This vulnerability is due to incorrect validations of specific function arguments that are passed to the boot script. An attacker could exploit this vulnerability by tampering with a specific file, which an affected device would process during the initial boot process. On systems that are protected by the Unified Extensible Firmware Interface (UEFI) secure boot feature, a successful exploit could allow the attacker to execute unsigned code at boot time and bypass the image verification check in the secure boot process of the affected device.

Weakness: CWE-489 (Active Debug Code)

## Which versions are affected by CVE-2021-1398?

It affects 1 product.


Products: Cisco Ios Xe.

## How do I fix CVE-2021-1398?

No fix has been published for CVE-2021-1398 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1398 being exploited?

There is no known exploitation of CVE-2021-1398 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios Xe

- [CVE-2023-20198](https://insights.sbomify.com/CVE-2023-20198/): Cisco IOS XE Web UI Privilege Escalation (critical 10.0, exploited in the wild)
- [CVE-2018-0151](https://insights.sbomify.com/CVE-2018-0151/): Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2023-20273](https://insights.sbomify.com/CVE-2023-20273/): Cisco IOS XE Web UI Command Injection (high 7.2, exploited in the wild)
- [CVE-2025-20188](https://insights.sbomify.com/CVE-2025-20188/): Hardcoded credentials in Cisco IOS XE Software (critical 10.0)
- [CVE-2021-34770](https://insights.sbomify.com/CVE-2021-34770/): Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1398 and fix it if it is affected.

What it is: CVE-2021-1398 is a medium-severity code injection vulnerability in Cisco Ios Xe, published on 24 Mar 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-2021-1398 in the wild and no public exploit code.

Affected product: Cisco Ios Xe. 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-2021-1398/ (Markdown: https://insights.sbomify.com/CVE-2021-1398/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1398
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1398
- OSV: https://osv.dev/vulnerability/CVE-2021-1398

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-1398/
Summaries are generated and may contain mistakes; the official description above is the record.