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

Summary

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.

Timeline

1. Nov 5, 2024, 10:06 PM UTCCVE published
2. Nov 6, 2024, 2:39 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Nov 6, 2024, 2:39 PM UTCRecord last updated

Affected versions

• bytecodealliance cap-std

  fixed in 3.4.1

• cap-primitivescrates.io

  From 0.0.0-0 · fixed in 3.4.1

• cap-stdcrates.io

  fixed in 3.4.1

• cap-async-stdcrates.io

  fixed in 3.4.1

• cap-primitivescrates.io

  fixed in 3.4.1

References 5