langchain/libs/community/langchain_community/retrievers/web_research.py
Eugene Yurtsev 604dfe2d99
community[patch]: Force opt-in for WebResearchRetriever (CVE-2024-3095) (#24451)
This PR addresses the issue raised by (CVE-2024-3095)

https://huntr.com/bounties/e62d4895-2901-405b-9559-38276b6a5273

Unfortunately, we didn't do a good job writing the initial report. It's
pointing at both the wrong package and the wrong code.

The affected code is the Web Retriever not the AsyncHTMLLoader, and the
WebRetriever lives in langchain-community

The vulnerable code lives here: 

0bd3f4e129/libs/community/langchain_community/retrievers/web_research.py (L233-L233)


This PR adds a forced opt-in for users to make sure they are aware of
the risk and can mitigate by configuring a proxy:


0bd3f4e129/libs/community/langchain_community/retrievers/web_research.py (L84-L84)
2024-07-19 18:51:35 +00:00

264 lines
9.8 KiB
Python

import logging
import re
from typing import Any, List, Optional
from langchain.chains import LLMChain
from langchain.chains.prompt_selector import ConditionalPromptSelector
from langchain_core.callbacks import (
AsyncCallbackManagerForRetrieverRun,
CallbackManagerForRetrieverRun,
)
from langchain_core.documents import Document
from langchain_core.language_models import BaseLLM
from langchain_core.output_parsers import BaseOutputParser
from langchain_core.prompts import BasePromptTemplate, PromptTemplate
from langchain_core.pydantic_v1 import BaseModel, Field
from langchain_core.retrievers import BaseRetriever
from langchain_core.vectorstores import VectorStore
from langchain_text_splitters import RecursiveCharacterTextSplitter, TextSplitter
from langchain_community.document_loaders import AsyncHtmlLoader
from langchain_community.document_transformers import Html2TextTransformer
from langchain_community.llms import LlamaCpp
from langchain_community.utilities import GoogleSearchAPIWrapper
logger = logging.getLogger(__name__)
class SearchQueries(BaseModel):
"""Search queries to research for the user's goal."""
queries: List[str] = Field(
..., description="List of search queries to look up on Google"
)
DEFAULT_LLAMA_SEARCH_PROMPT = PromptTemplate(
input_variables=["question"],
template="""<<SYS>> \n You are an assistant tasked with improving Google search \
results. \n <</SYS>> \n\n [INST] Generate THREE Google search queries that \
are similar to this question. The output should be a numbered list of questions \
and each should have a question mark at the end: \n\n {question} [/INST]""",
)
DEFAULT_SEARCH_PROMPT = PromptTemplate(
input_variables=["question"],
template="""You are an assistant tasked with improving Google search \
results. Generate THREE Google search queries that are similar to \
this question. The output should be a numbered list of questions and each \
should have a question mark at the end: {question}""",
)
class QuestionListOutputParser(BaseOutputParser[List[str]]):
"""Output parser for a list of numbered questions."""
def parse(self, text: str) -> List[str]:
lines = re.findall(r"\d+\..*?(?:\n|$)", text)
return lines
class WebResearchRetriever(BaseRetriever):
"""`Google Search API` retriever."""
# Inputs
vectorstore: VectorStore = Field(
..., description="Vector store for storing web pages"
)
llm_chain: LLMChain
search: GoogleSearchAPIWrapper = Field(..., description="Google Search API Wrapper")
num_search_results: int = Field(1, description="Number of pages per Google search")
text_splitter: TextSplitter = Field(
RecursiveCharacterTextSplitter(chunk_size=1500, chunk_overlap=50),
description="Text splitter for splitting web pages into chunks",
)
url_database: List[str] = Field(
default_factory=list, description="List of processed URLs"
)
trust_env: bool = Field(
False,
description="Whether to use the http_proxy/https_proxy env variables or "
"check .netrc for proxy configuration",
)
allow_dangerous_requests: bool = False
"""A flag to force users to acknowledge the risks of SSRF attacks when using
this retriever.
Users should set this flag to `True` if they have taken the necessary precautions
to prevent SSRF attacks when using this retriever.
For example, users can run the requests through a properly configured
proxy and prevent the crawler from accidentally crawling internal resources.
"""
def __init__(self, **kwargs: Any) -> None:
"""Initialize the retriever."""
allow_dangerous_requests = kwargs.get("allow_dangerous_requests", False)
if not allow_dangerous_requests:
raise ValueError(
"WebResearchRetriever crawls URLs surfaced through "
"the provided search engine. It is possible that some of those URLs "
"will end up pointing to machines residing on an internal network, "
"leading"
"to an SSRF (Server-Side Request Forgery) attack. "
"To protect yourself against that risk, you can run the requests "
"through a proxy and prevent the crawler from accidentally crawling "
"internal resources."
"If've taken the necessary precautions, you can set "
"`allow_dangerous_requests` to `True`."
)
super().__init__(**kwargs)
@classmethod
def from_llm(
cls,
vectorstore: VectorStore,
llm: BaseLLM,
search: GoogleSearchAPIWrapper,
prompt: Optional[BasePromptTemplate] = None,
num_search_results: int = 1,
text_splitter: RecursiveCharacterTextSplitter = RecursiveCharacterTextSplitter(
chunk_size=1500, chunk_overlap=150
),
trust_env: bool = False,
) -> "WebResearchRetriever":
"""Initialize from llm using default template.
Args:
vectorstore: Vector store for storing web pages
llm: llm for search question generation
search: GoogleSearchAPIWrapper
prompt: prompt to generating search questions
num_search_results: Number of pages per Google search
text_splitter: Text splitter for splitting web pages into chunks
trust_env: Whether to use the http_proxy/https_proxy env variables
or check .netrc for proxy configuration
Returns:
WebResearchRetriever
"""
if not prompt:
QUESTION_PROMPT_SELECTOR = ConditionalPromptSelector(
default_prompt=DEFAULT_SEARCH_PROMPT,
conditionals=[
(lambda llm: isinstance(llm, LlamaCpp), DEFAULT_LLAMA_SEARCH_PROMPT)
],
)
prompt = QUESTION_PROMPT_SELECTOR.get_prompt(llm)
# Use chat model prompt
llm_chain = LLMChain(
llm=llm,
prompt=prompt,
output_parser=QuestionListOutputParser(),
)
return cls(
vectorstore=vectorstore,
llm_chain=llm_chain,
search=search,
num_search_results=num_search_results,
text_splitter=text_splitter,
trust_env=trust_env,
)
def clean_search_query(self, query: str) -> str:
# Some search tools (e.g., Google) will
# fail to return results if query has a
# leading digit: 1. "LangCh..."
# Check if the first character is a digit
if query[0].isdigit():
# Find the position of the first quote
first_quote_pos = query.find('"')
if first_quote_pos != -1:
# Extract the part of the string after the quote
query = query[first_quote_pos + 1 :]
# Remove the trailing quote if present
if query.endswith('"'):
query = query[:-1]
return query.strip()
def search_tool(self, query: str, num_search_results: int = 1) -> List[dict]:
"""Returns num_search_results pages per Google search."""
query_clean = self.clean_search_query(query)
result = self.search.results(query_clean, num_search_results)
return result
def _get_relevant_documents(
self,
query: str,
*,
run_manager: CallbackManagerForRetrieverRun,
) -> List[Document]:
"""Search Google for documents related to the query input.
Args:
query: user query
Returns:
Relevant documents from all various urls.
"""
# Get search questions
logger.info("Generating questions for Google Search ...")
result = self.llm_chain({"question": query})
logger.info(f"Questions for Google Search (raw): {result}")
questions = result["text"]
logger.info(f"Questions for Google Search: {questions}")
# Get urls
logger.info("Searching for relevant urls...")
urls_to_look = []
for query in questions:
# Google search
search_results = self.search_tool(query, self.num_search_results)
logger.info("Searching for relevant urls...")
logger.info(f"Search results: {search_results}")
for res in search_results:
if res.get("link", None):
urls_to_look.append(res["link"])
# Relevant urls
urls = set(urls_to_look)
# Check for any new urls that we have not processed
new_urls = list(urls.difference(self.url_database))
logger.info(f"New URLs to load: {new_urls}")
# Load, split, and add new urls to vectorstore
if new_urls:
loader = AsyncHtmlLoader(
new_urls, ignore_load_errors=True, trust_env=self.trust_env
)
html2text = Html2TextTransformer()
logger.info("Indexing new urls...")
docs = loader.load()
docs = list(html2text.transform_documents(docs))
docs = self.text_splitter.split_documents(docs)
self.vectorstore.add_documents(docs)
self.url_database.extend(new_urls)
# Search for relevant splits
# TODO: make this async
logger.info("Grabbing most relevant splits from urls...")
docs = []
for query in questions:
docs.extend(self.vectorstore.similarity_search(query))
# Get unique docs
unique_documents_dict = {
(doc.page_content, tuple(sorted(doc.metadata.items()))): doc for doc in docs
}
unique_documents = list(unique_documents_dict.values())
return unique_documents
async def _aget_relevant_documents(
self,
query: str,
*,
run_manager: AsyncCallbackManagerForRetrieverRun,
) -> List[Document]:
raise NotImplementedError