Ollama Denial-of-Service Vulnerability in GGUF Decoder

A denial-of-service vulnerability has been identified in Ollama version 0.12.10. This issue allows remote attackers to cause the server to panic and terminate by exploiting the GGUF decoder. The vulnerability arises because the decoder does not properly validate the length of data before allocating memory, leading to a runtime error that crashes the process. The issue can be reproduced by uploading a malicious GGUF file that triggers the unchecked length handling.

Impact

Exploitation of this vulnerability causes a process crash, terminating the server instance.

Reproduction

The vulnerability can be reproduced by uploading a crafted GGUF file that exploits the length handling in the GGUF decoder. This can be done using the Ollama command-line interface to create a model with the malicious GGUF file. The server will panic with a 'makeslice: len out of range' error, indicating that the unchecked length has caused a runtime error.