PraisonAI: [Path Traversal] agent tools escape the configured workspace via symlinks
🔗 CVE IDs covered (1)
📋 Description
Summary
PraisonAI's praisonai.code tool wrappers (exported as CODE_TOOLS for agents) expose a workspace setting that the module itself treats as a path-traversal security boundary — read_file, write_file, apply_diff, and search_replace explicitly call is_path_within_directory() and return "… is outside the workspace" on violations. That boundary is enforced unsoundly and inconsistently:
- The containment helper uses
os.path.abspath(), notrealpath()/Path.resolve(). A symlink located inside the workspace whose target is outside has anabspath()that is still inside the workspace, so it passes the check whileopen()follows the link. This bypasses read, write, apply_diff, and search_replace (CWE-59). list_files()resolvespathagainst the workspace but never calls the containment helper at all —../and absolute paths escape directly (CWE-22).execute_command()takes aworkspaceargument documented "for security validation" but performs nocwdcontainment check;code_execute_command()resolves a relativecwdagainst the workspace and also never validates it (and never even passesworkspaceto the low-level helper). A relativecwd="../outside"runs commands from outside the workspace (CWE-22). An attacker who can influence an agent that has these tools attached (untrusted prompt, indirect prompt injection, or a server-exposed agent) can read, overwrite, list, and execute from outside the configured workspace, bounded only by the process user's filesystem permissions.
Technical Detail
1. Unsound containment helper (symlink bypass — CWE-59)
# src/praisonai/praisonai/code/utils/file_utils.py — is_path_within_directory()
abs_file = os.path.abspath(file_path) # does NOT resolve symlinks
abs_dir = os.path.abspath(directory)
if not abs_dir.endswith(os.sep): abs_dir += os.sep
return abs_file.startswith(abs_dir) or abs_file == abs_dir.rstrip(os.sep)
read_file/write_file/apply_diff/search_replace call this with the configured workspace (e.g. read_file.py: # Security check - ensure path is within workspace). Because abspath() does not canonicalize symlinks, a link at WORKSPACE/link_to_secret.txt → /outside/secret.txt has abspath WORKSPACE/link_to_secret.txt (inside) and passes, while open() follows it to the real outside target.
2. list_files() has no containment check (CWE-22)
# src/praisonai/praisonai/code/tools/list_files.py
if workspace and not os.path.isabs(path):
abs_path = os.path.abspath(os.path.join(workspace, path)) # ../ collapses out of workspace
else:
abs_path = os.path.abspath(path) # absolute path used as-is
# ... os.path.isdir(abs_path) then listed. is_path_within_directory() is NEVER called.
3. execute_command() never validates cwd (CWE-22)
# src/praisonai/praisonai/code/tools/execute_command.py — workspace param doc: "for security validation"
if cwd:
if workspace and not os.path.isabs(cwd):
work_dir = os.path.abspath(os.path.join(workspace, cwd)) # ../ escapes; no containment check
else:
work_dir = os.path.abspath(cwd)
# subprocess.run(args, cwd=work_dir, ...) # no is_path_within_directory() anywhere
# src/praisonai/praisonai/code/agent_tools.py — code_execute_command()
if work_dir and _workspace_root and not os.path.isabs(work_dir):
work_dir = os.path.join(_workspace_root, work_dir) # joins, never validates
result = _execute_command(command=command, cwd=work_dir, timeout=120) # workspace not even passed
Note: execute_command rejects shell=True and runs shlex.split(command) via subprocess.run (no shell), so shell metacharacters (&&, >, pipes) do not work — but any binary still runs with attacker-chosen argv from the escaped cwd, which is sufficient to read/write outside the workspace.
The workspace is an intended boundary (pre-empts "by design")
The module asserts this control itself: read_file.py "Security check - ensure path is within workspace"; write_file.py "default workspace is cwd so relative paths cannot escape"; is_path_within_directory docstring "(prevents path traversal)"; execute_command workspace param "for security validation". The bug is that the asserted control is unsound (abspath vs realpath) and not applied to list_files/execute_command cwd.
Proof of Concept
Self-contained, local temp fixtures only; no network, no untrusted commands. Real praisonai.code agent tools were called.
workspace = /tmp/.../workspace outside = /tmp/.../outside
[1] baseline plain ../ read -> BLOCKED: "Path '../outside/secret.txt' is outside the workspace"
[2] symlink read (in-WS link) -> SUCCESS: returned "SECRET_OUTSIDE_WORKSPACE"
[3] symlink write (in-WS link) -> SUCCESS: outside file now contains "OVERWRITTEN_VIA_SYMLINK"
[4] code_list_files("../outside") -> SUCCESS: "Contents of ../outside: 📄 secret.txt"
[5] code_execute_command(cwd="../outside","pwd") -> SUCCESS: stdout "/tmp/.../outside"
[6] code_execute_command(cwd="../outside", python3 -c open('planted.txt','w')...)
-> SUCCESS: new file created OUTSIDE workspace, "PWNED_OUTSIDE_WORKSPACE"
Steps 2–6 each cross the configured workspace boundary; step 1 shows the plain-../ guard that the symlink and unscoped vectors bypass.
Impact
- Confidentiality: read files outside the workspace (in-workspace symlink; or list/enumerate outside dirs via
list_files). - Integrity: overwrite outside files via symlink; create/modify files outside the workspace via
execute_commandrunning in an escaped cwd. - Execution boundary: run arbitrary available binaries (argv-controlled) from a directory outside the workspace. Bounded by the process user's permissions. In a code-agent or server-exposed agent processing untrusted input, this exposes secrets / project-adjacent / host files and breaks the project-boundary integrity guarantee the workspace setting advertises.
Suggested Fix
- Replace
is_path_within_directory()with arealpath()/Path.resolve()-based containment check, and compare withos.path.commonpath()rather thanstartswith. - Apply that check consistently to every file path, directory path, backup path, diff/search-replace target, and command working directory, after full canonicalization (resolve the symlink's real target, not the link path).
list_files(): reject absolute paths and../escapes whenworkspaceis set.execute_command(): validatecwdcontainment whenworkspaceis set;code_execute_command()should pass_workspace_rootto the low-level helper or validate itself.- Regression tests: symlink read/write/diff/search-replace to outside targets;
list_files("../outside", workspace=…);execute_command(cwd="../outside", workspace=…); absolute outside paths with a workspace set.
🎯 Affected products1
- pip/PraisonAI:< 4.6.58