CVE-2022-31100: rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Servic...

Description

rulex is a new, portable, regular expression language. 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. The crashes are fixed in version **0.4.3**. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.80%

51.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions
Pomsky-Lang	Pomsky	< 0.4.3

References

https://github.com/rulex-rs/rulex/commit/fac6d58b25c6f9f8c0a6cdc4dec75b37b219f1d6Patch, Third Party Advisory
https://github.com/rulex-rs/rulex/security/advisories/GHSA-8v9w-p43c-r885Mitigation, Third Party Advisory
https://github.com/rulex-rs/rulex/commit/fac6d58b25c6f9f8c0a6cdc4dec75b37b219f1d6Patch, Third Party Advisory
https://github.com/rulex-rs/rulex/security/advisories/GHSA-8v9w-p43c-r885Mitigation, Third Party Advisory

Timeline

Published: Jun 27, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-31100?

rulex is a new, portable, regular expression language. 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. The crashes are fixed in version **0.4.3**. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

How severe is CVE-2022-31100?

CVE-2022-31100 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.80% probability of exploitation in the next 30 days.

How do I fix CVE-2022-31100?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.