vulnerability / NVI-00016077 / Revision 1
PraisonAI: execute_code sandbox bypass: str.format C-level attribute access reads every blocklisted dunder
GitHub lists this reviewed advisory for praisonaiagents. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.5 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
praisonaiagents
source listed< 1.6.59
## Summary The `execute_code` tool's subprocess sandbox advertises a three-layer defense (AST validation, text-pattern blocklist, restricted `__builtins__`). In **sandbox mode** (the default) only two layers are active — the text-pattern blocklist is skipped — and both remaining layers are bypassed by combining two CPython semantics: 1. **Runtime string assembly.** The AST validator (`src/praisonai-agents/praisonaiagents/tools/python_tools.py:75`) enumerates blocked dunder names against `ast.Attribute.attr`, `ast.Call.func.id`, and `ast.Constant` string-substring. Names assembled at runtime (e.g. `"_"*2 + "class" + "_"*2`) appear in the AST as multiple short `ast.Constant` nodes, none containing a blocked substring, so the static check passes. 2. **C-level attribute access via format-spec.** `str.format` / `str.format_map` resolve dotted field references through CPython's internal `PyObject_GetAttr` (`do_string_format` → `get_field`). This C path never consults the Python-level `getattr` binding. The sandbox's `_safe_getattr` wrapper (`python_tools.py:221`) is installed only as the `getattr` name in `safe_builtins`, so any C-level attribute access — including format-spec field re
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-pv2j-rghr-v5r9 ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
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