Use of Cryptographically Weak Pseudo-Random Number Generator in Delta Electronics COMMGR

1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

EUVDB-ID: #VU107860

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-3495

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the affected software uses insufficiently randomized values to generate session IDs within the PLC simulator service. A remote attacker can brute force a session ID and execute arbitrary code on the system.

Mitigation

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

COMMGR: 1 - 2

CPE2.3

• cpe:2.3:a:delta_electronics:commgr:1:*:*:*:*:*:*:*
• cpe:2.3:a:delta_electronics:commgr:2:*:*:*:*:*:*:*

External links

https://filecenter.deltaww.com/news/download/doc/Delta-PCSA-2025-00005_COMMGR%20-%20Insufficient%20Randomization%20Authentication%20Bypass_v1.pdf
https://www.cisa.gov/news-events/ics-advisories/icsa-25-105-07
https://www.zerodayinitiative.com/advisories/ZDI-25-397/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.