BabelDOC is a document translation tool. Prior to 0.6.3, BabelDOC's vendored PDF parser in babeldoc/pdfminer/cmapdb.py deserializes untrusted pickle data when CMapDB._load_data() loads CMap files. PDF-controlled Encoding or CMapName values and embedded PostScript usecmap operators can reach this sink after path separators are decoded, while _normalize_cmap_name() removes only a leading slash. Absolute paths or traversal sequences can escape the trusted CMap directories through os.path.join(), select an attacker-writable .pickle.gz file, and cause pickle.loads() to execute arbitrary Python code with the privileges of the BabelDOC process. This issue is fixed in version 0.6.3.

Affected: PyPI: BabelDOC

## Arbitrary Code Execution via CMap Pickle Deserialization in babeldoc/pdfminer/cmapdb.py

### Summary

BabelDOC's vendored PDF parser (`babeldoc/pdfminer/cmapdb.py`) deserializes untrusted pickle data when loading CMap files. The `_load_data()` method strips only NUL bytes from a PDF-controlled CMap name, then passes it directly to `os.path.join()` and `pickle.loads()`. Because Python's `os.path.join()` discards all preceding path components when it encounters an absolute path segment, an attacker who embeds a hex-encoded absolute path in a crafted PDF's `/Encoding` name (e.g., `/#2Ftmp#2Fattacker#2Fevil`) can redirect deserialization to any attacker-writable `.pickle.gz` file on the local system. Processing such a PDF results in arbitrary Python code execution with the privileges of the BabelDOC process.

### Details

The vulnerable function is `CMapDB._load_data()` at `babeldoc/pdfminer/cmapdb.py:232–245`:

```python @classmethod def _load_data(cls, name: str) -> Any: name = name.replace("\0", "") # line 233 — only NUL is stripped filename = "%s.pickle.gz" % name # line 234 — attacker-controlled string ... for directory in cmap_paths: path = os.path.join(directory, filename) # line 241 — no realpath/canonical check if os.path.exists(path): gzfile = gzip.open(path) try: return type(str(name), (), pickle.loads(gzfile.read())) # line 245 — unconditional pickle ```

**Path injection via…

Affected: PyPI: babeldoc

## Arbitrary Code Execution via CMap Pickle Deserialization in babeldoc/pdfminer/cmapdb.py

### Summary

BabelDOC's vendored PDF parser (`babeldoc/pdfminer/cmapdb.py`) deserializes untrusted pickle data when loading CMap files. The `_load_data()` method strips only NUL bytes from a PDF-controlled CMap name, then passes it directly to `os.path.join()` and `pickle.loads()`. Because Python's `os.path.join()` discards all preceding path components when it encounters an absolute path segment, an attacker who embeds a hex-encoded absolute path in a crafted PDF's `/Encoding` name (e.g., `/#2Ftmp#2Fattacker#2Fevil`) can redirect deserialization to any attacker-writable `.pickle.gz` file on the local system. Processing such a PDF results in arbitrary Python code execution with the privileges of the BabelDOC process.

### Details

The vulnerable function is `CMapDB._load_data()` at `babeldoc/pdfminer/cmapdb.py:232–245`:

```python @classmethod def _load_data(cls, name: str) -> Any: name = name.replace("\0", "") # line 233 — only NUL is stripped filename = "%s.pickle.gz" % name # line 234 — attacker-controlled string ... for directory in cmap_paths: path = os.path.join(directory, filename) # line 241 — no realpath/canonical check if os.path.exists(path): gzfile = gzip.open(path) try: return type(str(name), (), pickle.loads(gzfile.read())) # line 245 — unconditional pickle ```

**Path injection via…