CVE-2022-35411: rpc.py Unauthenticated Remote Code Execution via Pickle Deserialization

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 20 September 2026. Confidence: high.

critical priorityCVSS 9.8 with network reachability, no authentication or user interaction, public exploit code and very high EPSS make this an urgent remote code execution risk.

What it is

rpc.py through 0.6.0 deserializes request data with Python pickle when a client sends the HTTP header "serializer: pickle", even though JSON is the default format. Because pickle deserialization can execute arbitrary code, an unauthenticated remote client can achieve remote code execution on the server.

Impact

An attacker gains arbitrary code execution in the context of the rpc.py server process, leading to full compromise of confidentiality, integrity and availability of the host and any data it can reach.

Attack surface

Reachable over the network via HTTP requests to the rpc.py service; no authentication or user interaction is required, as the CVSS vector shows AV:N/PR:N/UI:N and the description states an unauthenticated client can trigger unpickling.

Exploitation

Public exploit code and write-ups are referenced (packetstormsecurity, ehtec/rpcpy-exploit, Medium), and EPSS is 0.46139 (98.7th percentile), indicating high likelihood of exploitation; CVE-2022-35411 is not listed in CISA KEV.

What to do

• Upgrade rpc.py past 0.6.0 to the patched version referenced in the vendor commit 491e7a841ed9a754796d6ab047a9fb16e23bf8bd.
• If upgrade is not immediately possible, block or strip the "serializer: pickle" HTTP header at the reverse proxy or WAF and reject requests carrying it.
• Restrict network access to the rpc.py service to trusted clients only.
• Run the rpc.py service with least privilege and in a sandboxed/containerized environment to limit the impact of code execution.
• Monitor for and remove any exposed rpc.py instances that cannot be patched or isolated.

Detection

• Search HTTP request logs for the header "serializer: pickle" or any non-default serializer value sent to rpc.py endpoints.
• Monitor for unexpected child processes, shell commands or outbound connections spawned by the rpc.py server process.
• Use application or network monitoring to alert on pickle-formatted payloads or unusually large binary request bodies to the rpc.py service.
• Review server logs for errors or crashes associated with deserialization of request data.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.