CVE-2022-23514 is a vulnerability identified in the flavorjones loofah library, specifically versions prior to 2.19.1. Loofah is a widely used Ruby library designed for manipulating and sanitizing HTML and XML documents, built on top of the Nokogiri parsing library. The vulnerability arises from an inefficient regular expression used to sanitize certain SVG attributes. This inefficient regex leads to excessive backtracking, which can be exploited to cause a denial of service (DoS) condition by consuming excessive CPU resources. The root cause is classified under CWE-1333, which pertains to inefficient regular expression complexity. When maliciously crafted SVG content is processed by vulnerable versions of loofah, the regex engine may enter a state of exponential backtracking, significantly degrading performance and potentially leading to application unresponsiveness or crashes. This vulnerability does not require authentication or user interaction beyond the processing of malicious input, and no known public exploits have been reported to date. The issue was patched in version 2.19.1 of loofah, which addresses the regex inefficiency to prevent excessive backtracking and mitigate the DoS risk.

For European organizations, the primary impact of this vulnerability is the potential for denial of service attacks against applications that utilize vulnerable versions of the loofah library for HTML/XML sanitization, particularly those processing user-supplied SVG content. Such applications could include web services, content management systems, or any software that sanitizes SVG or HTML/XML inputs to prevent injection attacks. A successful exploitation could lead to service outages, degraded performance, or increased operational costs due to resource exhaustion. While the vulnerability does not directly compromise confidentiality or integrity, the availability impact could disrupt business operations, especially for organizations relying on web-facing applications or APIs that process SVG content. This could affect sectors such as media, publishing, e-commerce, and any enterprise leveraging Ruby-based web frameworks. Given the absence of known exploits, the risk is currently moderate but could increase if exploit code becomes available. Additionally, denial of service conditions could be leveraged as part of multi-vector attacks or to distract security teams during other malicious activities.

European organizations should immediately audit their software dependencies to identify any usage of the loofah library versions prior to 2.19.1. Upgrading to version 2.19.1 or later is the primary and most effective mitigation. For organizations unable to upgrade promptly, implementing input validation or filtering to restrict or sanitize SVG content before it reaches the loofah processing stage can reduce exposure. Monitoring application performance metrics and setting thresholds for CPU usage can help detect potential exploitation attempts early. Additionally, employing web application firewalls (WAFs) with rules to detect and block suspicious SVG payloads may provide a temporary protective layer. Developers should review their sanitization workflows to ensure that untrusted SVG inputs are handled cautiously. Finally, organizations should maintain an inventory of Ruby gems and their versions to facilitate timely patching and vulnerability management.