---
title: "Security digest: March 24, 2021"
url: https://erroneo.us/security/2021-03-24/
description: "March 24, 2021 vulnerability digest: 1 brief (DD-WRT CVE-2021-27137: UPnP Overflow Used by…). What to patch and who can relax."
type: security-digest-day
section: "Security Digest"
date_published: 2021-03-24
date_modified: 2026-07-21
publisher: erroneo.us
author: erroneo.us Security Desk
license: All rights reserved. Quote with attribution and a link.
---

# Security digest: March 24, 2021

1 editorial brief.

## Take stock

- Check exposure: DD-WRT CVE-2021-27137: UPnP Overflow Used by C0XMO Botnet . Owners of routers running DD-WRT builds before 45724, including Buffalo models that ship DD-WRT firmware, especially where UPnP is enabled or the device has not been updated since 2021.
- None of it touches your stack? Then there is nothing to do today. That is a result, not a failure to read carefully.

## Editorial briefs

- **Check exposure** [DD-WRT CVE-2021-27137: UPnP Overflow Used by C0XMO Botnet](https://erroneo.us/security/briefs/dd-wrt-upnp-ssdp-overflow-cve-2021-27137/index.md): Only routers running an old DD-WRT build with UPnP turned on are at risk; find any you own, update or retire them, and switch UPnP off where nobody needs it.

## Known exploited (CISA KEV)

None.

## Critical advisories

None.

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Source page: https://erroneo.us/security/2021-03-24/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt