Elysia Framework Regular Expression Denial-of-Service Vulnerability

A regular expression denial-of-service (ReDoS) vulnerability has been identified in the Elysia framework, specifically in versions prior to 1.4.26. The issue arises in the string validation function when the 'url' format is used. The vulnerability can be exploited by repeating a partial URL format, including the protocol and hostname, which causes significant slowdowns in regex processing. This issue has been addressed in version 1.4.26.

Impact

Exploitation of this vulnerability leads to a significant degradation in performance, causing delays in processing that can be exploited to create a denial-of-service condition.

Reproduction

The vulnerability can be reproduced by using the Elysia framework's string validation feature with the 'url' format. By repeating a partial URL, such as 'http://a', a denial-of-service condition can be created as the regular expression processing time increases exponentially with the number of repetitions.

Remediation

Users are advised to update the Elysia framework to version 1.4.26 or later. If an immediate update is not possible, a workaround is to limit the URL format to a reasonable length or to manually patch the URL format validation.