The vulnerability is a memory access flaw in nDPI 5.1.0’s DNS dissector and serializer deserialization code. When an attacker sends specially crafted DNS traffic, byte‑buffer addresses at odd offsets are cast to integer pointers (uint16_t or larger) and dereferenced without proper alignment checks. This undefined behavior can crash the application on strict‑alignment architectures or builds instrumented with UBSan, resulting in a denial of service.

The affected product is the nDPI network traffic analyzer, version 5.1.0. No other versions or vendor information are specified in the advisory. The vulnerability represents a critical flaw in the parsing logic for DNS packets.

The CVSS score is 7.5, indicating high severity. The EPSS score is < 1%, and the vulnerability is not listed in the CISA KEV catalog. The flaw can be exploited remotely by sending malicious DNS packets over the network, allowing an attacker to interrupt or crash the nDPI process. As a result, the service becomes unavailable until restarted, which may impact monitoring and traffic analysis operations.