CVE-2023-42524 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 implement file scanning engines. The issue manifests as an infinite loop within the scanning engine when processing unspecified file types, creating a scenario where legitimate security operations become paralyzed. The affected product lineup spans across desktop, server, and mobile platforms including Windows, macOS, and Linux environments, indicating a widespread impact across the organization's security infrastructure. This flaw essentially allows an attacker to craft malicious file inputs that will cause the security scanning process to enter an endless execution cycle, consuming system resources and rendering the security solution ineffective.
The technical nature of this vulnerability stems from inadequate input validation and error handling within the file processing components of the security scanning engine. When the engine encounters file types that are not properly handled or recognized, it fails to implement proper termination conditions for processing loops, leading to the infinite execution state. This type of vulnerability falls under the category of resource exhaustion attacks where system resources are consumed indefinitely, and the behavior aligns with CWE-835, which specifically addresses infinite loops in software implementations. The vulnerability represents a fundamental flaw in the scanning engine's robustness and demonstrates poor defensive programming practices that should be addressed through proper input sanitization and loop termination mechanisms.
The operational impact of this vulnerability is severe and multifaceted, potentially compromising the entire security posture of affected organizations. When the scanning engine enters an infinite loop, it consumes CPU cycles and memory resources continuously, leading to system performance degradation and potential complete system unresponsiveness. This creates a window of opportunity for malicious actors to bypass security controls entirely since the protection mechanisms are effectively disabled during the loop execution. Organizations relying on these security products may experience complete loss of protection against malware and other threats, while system administrators face challenges in identifying and resolving the issue due to the resource consumption characteristics. The vulnerability also impacts availability and integrity aspects of the security infrastructure, potentially violating compliance requirements and service level agreements.
Mitigation strategies for this vulnerability should focus on immediate patch deployment from WithSecure, as the vendor has likely released security updates addressing the infinite loop condition. Organizations should implement network segmentation and monitoring to detect unusual resource consumption patterns that might indicate exploitation attempts. The security team should establish baseline performance metrics for scanning engines to quickly identify when systems are entering problematic states. Additionally, implementing file type restrictions and content filtering at network boundaries can provide additional layers of protection. From an ATT&CK framework perspective, this vulnerability maps to technique T1499.004 for resource exhaustion and T1566.001 for spearphishing attachments, emphasizing the need for both preventive and detective controls. Organizations should also consider implementing automated alerting systems that trigger when scanning engine resource usage exceeds normal thresholds, providing early warning capabilities for potential exploitation attempts.