Vulnerabilities

RUSTSEC-2024-0421

idna accepts Punycode labels that do not produce any non-ASCII when decoded

idna 0.5.0 and earlier accepts Punycode labels that do not produce any non-ASCII output, which means that either ASCII labels or the empty root label can be masked such that they appear unequal without IDNA processing or when processed with a different implementation and equal when processed with idna 0.5.0 or earlier.

Concretely, example.org and xn--example-.org become equal after processing by idna 0.5.0 or earlier. Also, example.org.xn-- and example.org. become equal after processing by idna 0.5.0 or earlier.

In applications using idna (but not in idna itself) this may be able to lead to privilege escalation when host name comparison is part of a privilege check and the behavior is combined with a client that resolves domains with such labels instead of treating them as errors that preclude DNS resolution / URL fetching and with the attacker managing to introduce a DNS entry (and TLS certificate) for an xn---masked name that turns into the name of the target when processed by idna 0.5.0 or earlier.

Remedy

Upgrade to idna 1.0.3 or later, if depending on idna directly, or to url 2.5.4 or later, if depending on idna via url. (This issue was fixed in idna 1.0.0, but versions earlier than 1.0.3 are not recommended for other reasons.)

When upgrading, please take a moment to read about alternative Unicode back ends for idna.

If you are using Rust earlier than 1.81 in combination with SQLx 0.8.2 or earlier, please also read an issue about combining them with url 2.5.4 and idna 1.0.3.

Additional information

This issue resulted from idna 0.5.0 and earlier implementing the UTS 46 specification literally on this point and the specification having this bug. The specification bug has been fixed in revision 33 of UTS 46.

Acknowledgements

Thanks to kageshiron for recognizing the security implications of this behavior.

RUSTSEC-2024-0421

idna accepts Punycode labels that do not produce any non-ASCII when decoded

idna 0.5.0 and earlier accepts Punycode labels that do not produce any non-ASCII output, which means that either ASCII labels or the empty root label can be masked such that they appear unequal without IDNA processing or when processed with a different implementation and equal when processed with idna 0.5.0 or earlier.

Concretely, example.org and xn--example-.org become equal after processing by idna 0.5.0 or earlier. Also, example.org.xn-- and example.org. become equal after processing by idna 0.5.0 or earlier.

In applications using idna (but not in idna itself) this may be able to lead to privilege escalation when host name comparison is part of a privilege check and the behavior is combined with a client that resolves domains with such labels instead of treating them as errors that preclude DNS resolution / URL fetching and with the attacker managing to introduce a DNS entry (and TLS certificate) for an xn---masked name that turns into the name of the target when processed by idna 0.5.0 or earlier.

Remedy

Upgrade to idna 1.0.3 or later, if depending on idna directly, or to url 2.5.4 or later, if depending on idna via url. (This issue was fixed in idna 1.0.0, but versions earlier than 1.0.3 are not recommended for other reasons.)

When upgrading, please take a moment to read about alternative Unicode back ends for idna.

If you are using Rust earlier than 1.81 in combination with SQLx 0.8.2 or earlier, please also read an issue about combining them with url 2.5.4 and idna 1.0.3.

Additional information

This issue resulted from idna 0.5.0 and earlier implementing the UTS 46 specification literally on this point and the specification having this bug. The specification bug has been fixed in revision 33 of UTS 46.

Acknowledgements

Thanks to kageshiron for recognizing the security implications of this behavior.

RUSTSEC-2025-0004

ssl::select_next_proto use after free

In openssl versions before 0.10.70, ssl::select_next_proto can return a slice pointing into the server argument's buffer but with a lifetime bound to the client argument. In situations where the server buffer's lifetime is shorter than the client buffer's, this can cause a use after free. This could cause the server to crash or to return arbitrary memory contents to the client.

openssl 0.10.70 fixes the signature of ssl::select_next_proto to properly constrain the output buffer's lifetime to that of both input buffers.

In standard usage of ssl::select_next_proto in the callback passed to SslContextBuilder::set_alpn_select_callback, code is only affected if the server buffer is constructed within the callback. For example:

Not vulnerable - the server buffer has a 'static lifetime:

builder.set_alpn_select_callback(|_, client_protos| {
    ssl::select_next_proto(b"\x02h2", client_protos).ok_or_else(AlpnError::NOACK)
});

Not vulnerable - the server buffer outlives the handshake:

let server_protos = b"\x02h2".to_vec();
builder.set_alpn_select_callback(|_, client_protos| {
    ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK)
});

Vulnerable - the server buffer is freed when the callback returns:

builder.set_alpn_select_callback(|_, client_protos| {
    let server_protos = b"\x02h2".to_vec();
    ssl::select_next_proto(&server_protos, client_protos).ok_or_else(AlpnError::NOACK)
});

RUSTSEC-2024-0399

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.

Warnings

RUSTSEC-2024-0388

derivative is unmaintained; consider using an alternative

The derivative crate is no longer maintained.
Consider using any alternative, for instance:

• derive_more
• derive-where
• educe

RUSTSEC-2024-0384

instant is unmaintained

This crate is no longer maintained, and the author recommends using the maintained web-time crate instead.

RUSTSEC-2024-0370

proc-macro-error is unmaintained

proc-macro-error's maintainer seems to be unreachable, with no commits for 2 years, no releases pushed for 4 years, and no activity on the GitLab repo or response to email.

proc-macro-error also depends on syn 1.x, which may be bringing duplicate dependencies into dependant build trees.

Possible Alternative(s)

• manyhow
• proc-macro-error2
• proc-macro2-diagnostics

RUSTSEC-2021-0127

serde_cbor is unmaintained

The serde_cbor crate is unmaintained. The author has archived the github repository.

Alternatives proposed by the author:

• ciborium
• minicbor

Crate critical-section is yanked

No extra details provided.

Crate futures-util is yanked

No extra details provided.