ModelTC LightLLM through version 1.2.0 exposes an unauthenticated RPyC cache service that allows pickle deserialization on all interfaces. This insecure deserialization vulnerability enables remote attackers to send malicious serialized objects to the cache service, leading to arbitrary code execution with the privileges of the LightLLM service. The vulnerability has a CVSS 4.0 score of 9.3, indicating critical severity with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability.

Successful exploitation allows remote attackers to execute arbitrary code on the affected system with the privileges of the LightLLM service. This can lead to full compromise of the affected host, including data theft, service disruption, or further lateral movement within the environment.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict network access to the RPyC cache service to trusted hosts only and disable or limit pickle deserialization if possible to reduce exposure.