CVE-2025-27458: The VNC authentication mechanism bases on a challenge-response system where both server and client use the sam

Routine

MEDIUM 6.5MITIGATE

CVE-2025-27458 is a medium-severity flaw (CVSS 6.5) affecting meac300-fnade4 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The VNC authentication mechanism bases on a challenge-response system where both server and client use the same password for encryption. The challenge is sent from the server to the client, is encrypted by the client and sent back. The server does the same encryption locally and if the responses match it is prooven that the client knows the correct password. Since all VNC communication is unencrypted, an attacker can obtain the challenge and resp

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 90%)
CISA exploited list	No
Weakness	CWE-327
Published	2025-07-03
Last modified	2026-06-17

Publisher (CNA): SICK AG · Vendor: endress

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

Am I affected?

Timeline

2025-07-03 12:15 UTCPublished CVE record published
2026-06-17 09:03 UTCUpdated Record last modified

endress meac300-fnade4 firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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-2025-27458?

meac300-fnade4 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-27458 being exploited?

CVE-2025-27458 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-2025-27458 affect?

CVE-2025-27458 affects meac300-fnade4 firmware. Severity is medium (CVSS 6.5). The VNC authentication mechanism bases on a challenge-response system where both server and client use the same password for encryption. The challenge is sent from the server to the client, is encrypted by the client and sent back. The serv

How urgent is CVE-2025-27458?

Priority 25/100. No elevated risk signals yet.

Related CVEs

CVE-2025-27461 HIGH 7.6 MITIGATE During startup, the device automatically logs in the EPC2 Windows user without requesting a password.
CVE-2025-27460 HIGH 7.6 MITIGATE The hard drives of the device are not encrypted using a full volume encryption feature such as BitLocker
CVE-2025-27459 MEDIUM 4.4 MITIGATE The VNC application stores its passwords encrypted within the registry but uses DES for encryption
CVE-2025-27457 MEDIUM 6.5 MITIGATE All communication between the VNC server and client(s) is unencrypted
CVE-2025-27456 HIGH 7.5 MITIGATE The SMB server's login mechanism does not implement sufficient measures to prevent multiple failed authenticat

References

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