CVE-2025-27458
CVE-2025-27458
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 response and try to derive the password from this information.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.5
CVE-2025-27458
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 response and try to derive the password from this information.
- Record
CVE-2025-27458- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-327
- Updated
- 2026-11-02
EUVDEUVD-2025-19870
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 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 response and try to derive the password from this information.
- Record
EUVD-2025-19870- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hcwq-wcmg-w44r
6.5
The VNC authentication mechanism bases on a challenge-response system where both server and...
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 response and try to derive the password from this information.
- Record
GHSA-hcwq-wcmg-w44r- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-327
- Updated
- 2026-11-02
NVD
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 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 response and try to derive the password from this information.
- Record
CVE-2025-27458- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-327
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-27458 is a medium vulnerability (CVSS 6.5) in Endress Meac300-fnade4 Firmware, published July 3, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 10th percentile. No source names a fixed version.
References
endress.com
sick.com/psirt
cisa.gov/resources-tools/resources/ics-recommended-practices
first.org/cvss/calculator/3.1
sick.com/.well-known/csaf/white/2025/sca-2025-0008.json
sick.com/.well-known/csaf/white/2025/sca-2025-0008.pdf
nvd.nist.gov/vuln/detail/CVE-2025-27458
github.com/advisories/GHSA-hcwq-wcmg-w44r