Affected versions of this crate is not panic safe within callback functions stream_callback and stream_finished_callback.

The call to user-provided closure might panic before a mem::forget call, which then causes a use after free that grants attacker to control the callback function pointer.

This allows an attacker to construct an arbitrary code execution .

The flaw was reported by Phosphorus15.

On Windows, configuring a named pipe server with pipe_mode will force ServerOptions::reject_remote_clients as false.

This drops any intended explicit configuration for the reject_remote_clients that may have been set as true previously.

The default setting of reject_remote_clients is normally true meaning the default is also overridden as false.

Workarounds

Ensure that pipe_mode is set first after initializing a ServerOptions. For example:

let mut opts = ServerOptions::new();
opts.pipe_mode(PipeMode::Message);
opts.reject_remote_clients(true);

Impact

Due to a non-constant-time implementation, information about the private key is leaked through timing information which is observable over the network. An attacker may be able to use that information to recover the key.

Patches

No patch is yet available, however work is underway to migrate to a fully constant-time implementation.

Workarounds

The only currently available workaround is to avoid using the rsa crate in settings where attackers are able to observe timing information, e.g. local use on a non-compromised computer is fine.

References

This vulnerability was discovered as part of the "Marvin Attack", which revealed several implementations of RSA including OpenSSL had not properly mitigated timing sidechannel attacks.

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.