title: Uncontrolled Recursion in rulex
description: rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, the stack may overflow, possibly enabling a Denial of Service attack. This happens when parsing an expression with several hundred levels of nesting, causing the process to abort immediately. 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 process running rulex aborts due to a stack overflow. The crash is fixed in version **0.4.3**. Affected users are advised to update to this version. There are no known workarounds for this issue.
problem types: CWE-674: Uncontrolled Recursion
affected:
{
product: rulex
vendor: rulex-rs
versions:
status: affected, version: < 0.4.3
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]