Advisories for Cargo/Pyo3 package

PyO3 0.24.0 added optimized implementations of Iterator::nth and DoubleEndedIterator::nth_back for the BoundListIterator and BoundTupleIterator types. These implementations computed the target index using unchecked usize addition (index + n) before bounds-checking against the sequence length, then read the element via get_item_unchecked. In nth methods, a sufficiently large n (combined with a non-zero internal index) could cause the addition to overflow and wrap around, producing a small "target index" that passed the …

PyCFunction::new_closure (and the temporary new_closure_bound complement in the 0.21–0.22 series) required the supplied closure to be Send + 'static but not Sync. The resulting PyCFunction is a Python callable that can be invoked from any Python thread, which means the closure may be called concurrently from multiple threads, and needs a Sync bound to prevent possible data races. The problem exists under all Python versions but is particularly vulnerable under …

PyO3 0.28.1 added support for #[pyclass(extends=PyList)] struct NativeSub (and other native types) when targeting Python 3.12 and up with the abi3 feature. It was discovered that subclasses of such classes would use the type of the subclass when attempting to access to data of NativeSub contained within Python objects, amounting to memory corruption. PyO3 0.28.2 fixed the issue by using the type of (e.g.) NativeSub correctly.

PyString::from_object took &str arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the &str data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow). In PyO3 0.24.1 this function will now allocate a CString to guarantee a terminating …

In PyO3 0.23.0 the PYO3_CONFIG_FILE environment variable used to configure builds regressed such that changing the environment variable would no longer trigger PyO3 to reconfigure and recompile. In combination with workflows using tools such as maturin to build for multiple versions in a single build, this leads to Python wheels being compiled against the wrong Python API version. All users who distribute artefacts for multiple Python versions are encouraged to …

The family of functions to read "borrowed" values from Python weak references were fundamentally unsound, because the weak reference does itself not have ownership of the value. At any point the last strong reference could be cleared and the borrowed value would become dangling. In PyO3 0.22.4 these functions have all been deprecated and patched to leak a strong reference as a mitigation. PyO3 0.23 will remove these functions entirely.

The family of functions to read "borrowed" values from Python weak references were fundamentally unsound, because the weak reference does itself not have ownership of the value. At any point the last strong reference could be cleared and the borrowed value would become dangling. In PyO3 0.22.4 these functions have all been deprecated and patched to leak a strong reference as a mitigation. PyO3 0.23 will remove these functions entirely.

An issue was discovered in the pyo3 crate before 0.12.4 for Rust. There is a reference-counting error and use-after-free in From<Py>.