Reachable Assertion in rulex

### Impact When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if - your service parses untrusted rulex expressions (expressions provided by an untrusted user), and - your service becomes unavailable when the thread running rulex panics. ### Patches The crashes are fixed in version **0.4.3**. Affected users are advised to update to this version. ### Workarounds You can use `catch_unwind` to recover from panics. ### For more information If you have any questions or comments about this advisory: * Open an issue in [rulex](https://github.com/rulex-rs/rulex/issues) * Email me at [[email protected]](mailto:[email protected]) ### Credits Credit for finding these bugs goes to - [cargo fuzz](https://github.com/rust-fuzz/cargo-fuzz) and [afl.rs](https://github.com/rust-fuzz/afl.rs) - [evanrichter](https://github.com/evanrichter) - [ForAllSecure Mayhem](https://forallsecure.com/)

Source published

21 Jun 2022 20:12:15 UTC

Source modified

8 Nov 2023 04:09:26 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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