A vulnerability has been identified in Nucleus NET (All versions < V5.2), Nucleus RTOS (versions including affected DNS modules), Nucleus Source Code (versions including affected DNS modules), VSTAR (versions including affected DNS modules). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a write past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to execute code in the context of the current process or cause a denial-of-service condition.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-27009
• https://cert-portal.siemens.com/productcert/pdf/ssa-185699.pdf
• https://us-cert.cisa.gov/ics/advisories/icsa-21-103-04
• https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf