CVE-2021-25910: Improper Authentication vulnerability in the cookie parameter of ZIV AUTOMATION 4CCT-EA6-334126BF allows a loc

Routine

HIGH 8.0MITIGATE

CVE-2021-25910 is a high-severity flaw (CVSS 8.0) affecting 4cct-ea6-334126bf firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Authentication vulnerability in the cookie parameter of ZIV AUTOMATION 4CCT-EA6-334126BF allows a local attacker to perform modifications in several parameters of the affected device as an authenticated user.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.0 (High)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.5% (top 60%)
CISA exploited list	No
Weakness	CWE-287
Published	2021-01-29
Last modified	2026-06-17

Publisher (CNA): Spanish National Cybersecurity Institute, S.A. (INCIBE) · Vendor: zivautomation

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-29 14:15 UTCPublished CVE record published
2026-06-17 03:42 UTCUpdated Record last modified

zivautomation 4cct-ea6-334126bf firmware MITIGATE

Affected: 3.23.77.8.33251

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.23.77.8.33251

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-25910?

4cct-ea6-334126bf firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-25910 being exploited?

CVE-2021-25910 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-25910 affect?

CVE-2021-25910 affects 4cct-ea6-334126bf firmware. Severity is high (CVSS 8.0). Improper Authentication vulnerability in the cookie parameter of ZIV AUTOMATION 4CCT-EA6-334126BF allows a local attacker to perform modifications in several parameters of the affected device as an authenticated user.

How urgent is CVE-2021-25910?

Priority 38/100. High severity

Related CVEs

CVE-2021-25909 HIGH 8.6 MITIGATE ZIV Automation 4CCT-EA6-334126BF firmware version 3.23.80.27.36371, allows an unauthenticated, remote attacker

References

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