This project might be open to known security vulnerabilities, which can be prevented by tightening the version range of affected dependencies. Find detailed information at the bottom.
Unix-like operating systems may segfault due to dereferencing a dangling pointer in specific circumstances. This requires an environment variable to be set in a different thread than the affected functions. This may occur without the user's knowledge, notably in a third-party library.
A bug introduced in rustls 0.23.13 leads to a panic if the received
TLS ClientHello is fragmented. Only servers that use
rustls::server::Acceptor::accept() are affected.
Servers that use tokio-rustls's LazyConfigAcceptor API are affected.
Servers that use tokio-rustls's TlsAcceptor API are not affected.
Servers that use rustls-ffi's rustls_acceptor_accept API are affected.
When user-provided input is provided to any type that parses with the RFC 2822 format, a denial of
service attack via stack exhaustion is possible. The attack relies on formally deprecated and
rarely-used features that are part of the RFC 2822 format used in a malicious manner. Ordinary,
non-malicious input will never encounter this scenario.
Patches
A limit to the depth of recursion was added in v0.3.47. From this version, an error will be returned
rather than exhausting the stack.
Workarounds
Limiting the length of user input is the simplest way to avoid stack exhaustion, as the amount of
the stack consumed would be at most a factor of the length of the input.
pyo3: Out-of-bounds read in `nth` / `nth_back` for `PyList` and `PyTuple` iterators
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 bounds check and enabling reads at the front
of the list or tuple of elements previously yielded by the iterator.
In nth_back methods, a sufficiently large n could cause underflow in a
similar fashion, however would instead allow reads of arbitrary memory past
the end of the list or tuple storage.
PyO3 0.29.0 has corrected these methods to use checked arithmetic at the
positions which could be at risk of overflow.
pyo3: Missing `Sync` bound on `PyCFunction::new_closure` closures
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
the newer free-threaded Python variant, which do not have serial execution
imposed by the Global Interpreter Lock. Under releases protected by the GIL,
the ability to "detach" from the Python interpreter temporarily inside the closure
(e.g. by Python::detach) makes it possible for interleaved and/or concurrent
execution of various portions of the closure.
PyO3 0.29.0 added a Sync bound to close this thread-safety bug.