CVE-2023-42525 in Client Security
Summary
by MITRE • 09/18/2023
Certain WithSecure products allow an infinite loop in a scanning engine via unspecified file types. This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, Linux Security 64 12.0 , Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 1.0.35-1.
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Analysis
by VulDB Data Team • 02/02/2026
This vulnerability represents a critical denial of service condition affecting multiple WithSecure security products that can be exploited through malicious file handling within their scanning engines. The flaw manifests as an infinite loop during file type processing, specifically when encountering unspecified file types that trigger recursive or iterative processing patterns within the security scanning infrastructure. The affected product line spans across desktop, server, and mobile security solutions including Client Security 15, Server Security 15, Email and Server Security 15, Elements Endpoint Protection 17 and later versions, as well as Mac and Linux variants. This vulnerability directly impacts the availability and operational integrity of security infrastructure, potentially allowing attackers to disrupt security operations through simple file-based attacks that cause systems to consume excessive CPU resources or become unresponsive. The infinite loop condition represents a classic software bug that can be exploited through crafted file inputs, leading to system resource exhaustion and service disruption.
The technical implementation of this vulnerability stems from insufficient input validation and error handling within the file scanning engine components of these security products. When processing unspecified or malformed file types, the scanning engine fails to properly terminate processing loops or implement appropriate timeout mechanisms, resulting in continuous execution of processing routines that consume system resources without progressing toward a valid scan conclusion. This behavior aligns with common software vulnerabilities categorized under CWE-835, which addresses infinite loops in software implementations where loop termination conditions are not properly enforced. The vulnerability demonstrates a lack of proper resource management and input sanitization that could be exploited by attackers to perform denial of service attacks against security infrastructure, potentially compromising the availability of critical security services.
From an operational perspective, this vulnerability presents significant risk to organizations relying on WithSecure products for endpoint and network protection. The infinite loop condition can cause complete system unresponsiveness or excessive resource consumption that prevents legitimate security scanning operations from completing successfully. Attackers could exploit this vulnerability by simply sending malicious files to systems running affected WithSecure products, causing system administrators to experience service disruptions and potentially leading to security gaps during the period when systems are unresponsive. The impact extends beyond simple service interruption as it can affect the overall security posture by preventing legitimate security operations from functioning properly, potentially allowing other threats to bypass detection due to the compromised scanning infrastructure. Organizations may also face operational challenges in identifying and resolving the issue, particularly when the vulnerability manifests as a system performance degradation rather than an obvious crash or error condition.
The recommended mitigation strategies focus on immediate product updates and patches provided by WithSecure to address the infinite loop condition in the scanning engines. Organizations should prioritize applying the vendor-provided security updates as soon as possible to eliminate the vulnerability and restore normal system functionality. Network administrators should also implement additional monitoring and alerting mechanisms to detect unusual resource consumption patterns that might indicate exploitation attempts. Security teams should consider implementing temporary network segmentation or file filtering policies to prevent potentially malicious files from reaching systems running affected software versions. Additionally, organizations should review their incident response procedures to ensure appropriate handling of potential exploitation attempts and maintain backup scanning capabilities to ensure continuous security monitoring during patch deployment periods. This vulnerability highlights the importance of proper input validation and resource management in security software, as well as the critical need for regular security updates to address emerging threats in security infrastructure components. The issue also demonstrates the broader implications of software quality assurance in security products where even seemingly minor implementation flaws can result in significant operational impacts and security posture degradation.