CVE-2021-27393

A vulnerability has been identified in Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2013.08), Nucleus Source Code (Versions including affected DNS modules). The DNS client does not properly randomize UDP port numbers of DNS requests. That could allow an attacker to poison the DNS cache or spoof DNS resolving.

• CWE-330
• CWE-330

• https://cert-portal.siemens.com/productcert/pdf/ssa-201384.pdfVendor Advisory
• https://cert-portal.siemens.com/productcert/pdf/ssa-201384.pdfVendor Advisory

Published

Apr 22, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-27387A vulnerability has been identified in Simcenter Femap 2020.…7.8
• CVE-2021-27388SINAMICS medium voltage routable products are affected by a …9.8
• CVE-2021-27389A vulnerability has been identified in Opcenter Quality (All…9.8
• CVE-2021-27390A vulnerability has been identified in JT2Go (All versions <…7.8
• CVE-2021-27391A vulnerability has been identified in APOGEE MBC (PPC) (P2 …9.8
• CVE-2021-27392A vulnerability has been identified in Siveillance Video Ope…8.8
• CVE-2021-27394A vulnerability has been identified in Mendix Applications u…8.8
• CVE-2021-27395A vulnerability has been identified in SIMATIC Process Histo…8.1
• CVE-2021-27396A vulnerability has been identified in Tecnomatix Plant Simu…7.8
• CVE-2021-27397A vulnerability has been identified in Tecnomatix Plant Simu…7.8
• CVE-2021-27398A vulnerability has been identified in Tecnomatix Plant Simu…7.8
• CVE-2021-27399A vulnerability has been identified in Simcenter Femap 2020.…7.8