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.
The Rust Security Response WG was notified that the regex crate did not
properly limit the complexity of the regular expressions (regex) it parses. An
attacker could use this security issue to perform a denial of service, by
sending a specially crafted regex to a service accepting untrusted regexes. No
known vulnerability is present when parsing untrusted input with trusted
regexes.
This issue has been assigned CVE-2022-24713. The severity of this vulnerability
is "high" when the regex crate is used to parse untrusted regexes. Other uses
of the regex crate are not affected by this vulnerability.
Overview
The regex crate features built-in mitigations to prevent denial of service
attacks caused by untrusted regexes, or untrusted input matched by trusted
regexes. Those (tunable) mitigations already provide sane defaults to prevent
attacks. This guarantee is documented and it's considered part of the crate's
API.
Unfortunately a bug was discovered in the mitigations designed to prevent
untrusted regexes to take an arbitrary amount of time during parsing, and it's
possible to craft regexes that bypass such mitigations. This makes it possible
to perform denial of service attacks by sending specially crafted regexes to
services accepting user-controlled, untrusted regexes.
Affected versions
All versions of the regex crate before or equal to 1.5.4 are affected by this
issue. The fix is include starting from regex 1.5.5.
Mitigations
We recommend everyone accepting user-controlled regexes to upgrade immediately
to the latest version of the regex crate.
Unfortunately there is no fixed set of problematic regexes, as there are
practically infinite regexes that could be crafted to exploit this
vulnerability. Because of this, we do not recommend denying known problematic
regexes.
Acknowledgements
We want to thank Addison Crump for responsibly disclosing this to us according
to the Rust security policy, and for helping review the fix.
We also want to thank Andrew Gallant for developing the fix, and Pietro Albini
for coordinating the disclosure and writing this advisory.
rustls: rustls network-reachable panic in `Acceptor::accept`
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.