A vulnerability classified as problematic has been found in cronvel terminal-kit up to 2.1.7. Affected is an unknown function. The manipulation leads to inefficient regular expression complexity. Using CWE to declare the problem leads to CWE-1333. The weakness was published 01/07/2023 as a2e446cc3927b559d0281683feb9b821e83b758c. The advisory is shared for download at github.com. This vulnerability is traded as CVE-2021-4306. The attack needs to be initiated within the local network. There are no technical details available. There is no exploit available. The current price for an exploit might be approx. USD $0-$5k at the moment. The MITRE ATT&CK project declares the attack technique as T1449.003. It is declared as not defined. As 0-day the estimated underground price was around $0-$5k. Upgrading to version 2.1.8 is able to address this issue. The updated version is ready for download at github.com. The name of the patch is a2e446cc3927b559d0281683feb9b821e83b758c. The bugfix is ready for download at github.com. It is recommended to upgrade the affected component. A possible mitigation has been published before and not just after the disclosure of the vulnerability.