Summary
Reachable Assertion in rulex
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
- Email me at [email protected]
Credits
Credit for finding these bugs goes to
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.
CVE-2022-31100 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.4.3); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
The crashes are fixed in version 0.4.3. Affected users are advised to update to this version.
Frequently Asked Questions
- What is CVE-2022-31100? CVE-2022-31100 is a medium-severity security vulnerability in rulex (rust), affecting versions < 0.4.3. It is fixed in 0.4.3.
- How severe is CVE-2022-31100? CVE-2022-31100 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of rulex are affected by CVE-2022-31100? rulex (rust) versions < 0.4.3 is affected.
- Is there a fix for CVE-2022-31100? Yes. CVE-2022-31100 is fixed in 0.4.3. Upgrade to this version or later.
- Is CVE-2022-31100 exploitable, and should I be worried? Whether CVE-2022-31100 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2022-31100 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2022-31100? Upgrade
rulexto 0.4.3 or later.