CVE-2021-27420

GE UR family input validation

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.

Remediation

Solution:

  • GE strongly recommends users with impacted firmware versions update their UR devices to UR firmware Version 8.10, or greater to resolve these vulnerabilities. GE provides additional mitigations and information about these vulnerabilities in GE Publication Number: GES-2021-004 (login required).

Workaround:

  • GE recommends protecting UR IED by using network defense-in-depth practices. This includes, but is not limited to, placing UR IED inside the control system network security perimeter, and having access controls, monitoring (such as an Intrusion Detection System), and other mitigating technologies in place. GE recommends users refer to the UR Deployment guide for secure configuration of UR IED and system.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.21%
Vendor Advisory gegridsolutions.com
Affected: GE UR family
Published at:
Updated at:

References

Link Tags
https://www.cisa.gov/uscert/ics/advisories/icsa-21-075-02 mitigation third party advisory us government resource
https://www.gegridsolutions.com/Passport/Login.aspx vendor advisory permissions required

Frequently Asked Questions

What is the severity of CVE-2021-27420?
CVE-2021-27420 has been scored as a medium severity vulnerability.
How to fix CVE-2021-27420?
To fix CVE-2021-27420: GE strongly recommends users with impacted firmware versions update their UR devices to UR firmware Version 8.10, or greater to resolve these vulnerabilities. GE provides additional mitigations and information about these vulnerabilities in GE Publication Number: GES-2021-004 (login required).
Is CVE-2021-27420 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-27420 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-27420?
CVE-2021-27420 affects GE UR family.
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