If a tokio::sync::oneshot channel is closed (via the
oneshot::Receiver::close method), a data race may occur if the
oneshot::Sender::send method is called while the corresponding
oneshot::Receiver is awaited or calling try_recv.
When these methods are called concurrently on a closed channel, the two halves
of the channel can concurrently access a shared memory location, resulting in a
data race. This has been observed to cause memory corruption.
Note that the race only occurs when both halves of the channel are used
after the Receiver half has called close. Code where close is not used, or where the
Receiver is not awaited and try_recv is not called after calling close,
is not affected.
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
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.
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
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.
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.
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
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.