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.

Warnings

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-2024-0320

yaml-rust is unmaintained.

The maintainer seems unreachable.

Many issues and pull requests have been submitted over the years
without any response.

Alternatives

Consider switching to the actively maintained yaml-rust2 fork of the original project:

• yaml-rust2
• yaml-rust2 @ crates.io

Crate futures-util is yanked

No extra details provided.