When aborting a task with JoinHandle::abort, the future is dropped in the thread calling abort if the task is not currently being executed. This is incorrect for tasks spawned on a LocalSet.

This can easily result in race conditions as many projects use Rc or RefCell in their Tokio tasks for better performance.

See tokio#3929 for more details.

hyper's HTTP header parser accepted, according to RFC 7230, illegal contents inside Content-Length headers. Due to this, upstream HTTP proxies that ignore the header may still forward them along if it chooses to ignore the error.

To be vulnerable, hyper must be used as an HTTP/1 server and using an HTTP proxy upstream that ignores the header's contents but still forwards it. Due to all the factors that must line up, an attack exploiting this vulnerability is unlikely.

When decoding chunk sizes that are too large, hyper's code would encounter an integer overflow. Depending on the situation, this could lead to data loss from an incorrect total size, or in rarer cases, a request smuggling attack.

To be vulnerable, you must be using hyper for any HTTP/1 purpose, including as a client or server, and consumers must send requests or responses that specify a chunk size greater than 18 exabytes. For a possible request smuggling attack to be possible, any upstream proxies must accept a chunk size greater than 64 bits.

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.

See tokio#4225 for more details.

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.

Affected version of this crate did not properly parse unknown fields when parsing a user-supplied input.

This allows an attacker to cause a stack overflow when parsing the mssage on untrusted data.