CVE-2024-51756 cap-std doesn't fully sandbox all the Windows device filenames

What is CVE-2024-51756?

CVE-2024-51756 is a low-severity path traversal vulnerability in bytecodealliance cap-std, published on 5 Nov 2024. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

The cap-std project is organized around the eponymous `cap-std` crate, and develops libraries to make it easy to write capability-based code. cap-std's filesystem sandbox implementation on Windows blocks access to special device filenames such as "COM1", "COM2", "LPT0", "LPT1", and so on, however it did not block access to the special device filenames which use superscript digits, such as "COM¹", "COM²", "LPT⁰", "LPT¹", and so on. Untrusted filesystem paths could bypass the sandbox and access devices through those special device filenames with superscript digits, and through them provide access peripheral devices connected to the computer, or network resources mapped to those devices. This can include modems, printers, network printers, and any other device connected to a serial or parallel port, including emulated USB serial ports. The bug is fixed in #371, which is published in cap-primitives 3.4.1, cap-std 3.4.1, and cap-async-std 3.4.1. There are no known workarounds for this issue. Affected Windows users are recommended to upgrade.

Weakness: CWE-22

Which versions are affected by CVE-2024-51756?

7 open source packages ship an affected version, including cap-std, cap-async-std and cap-primitives.

How do I fix CVE-2024-51756?

Upgrade cap-std to 3.4.1 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2024-51756 being exploited?

There is no known exploitation of CVE-2024-51756 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-hxf5-99xg-86hw, RUSTSEC-2024-0445.