CVE-2023-24604 in OX App Suite
Summary
by MITRE • 05/29/2023
OX App Suite before backend 7.10.6-rev37 does not check HTTP header lengths when downloading, e.g., potentially allowing a crafted iCal feed to provide an unlimited amount of header data.
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Analysis
by VulDB Data Team • 10/24/2025
The vulnerability identified as CVE-2023-24604 affects OX App Suite versions prior to backend 7.10.6-rev37 and represents a critical security flaw in the application's handling of HTTP headers during file downloads. This issue specifically manifests when processing iCal feeds, which are commonly used for calendar data exchange and synchronization. The vulnerability stems from inadequate validation of HTTP header lengths, creating a potential avenue for attackers to exploit the system through crafted malicious data streams. The flaw allows for unlimited header data to be processed, which can lead to various security and operational consequences within the affected environment.
The technical implementation of this vulnerability involves the application's failure to enforce reasonable limits on HTTP header sizes when processing incoming data streams. When OX App Suite downloads calendar data through iCal feeds, it should validate and constrain the size of HTTP headers to prevent resource exhaustion or injection attacks. However, the absence of such validation allows attackers to craft malicious iCal feeds containing excessively long HTTP headers that can overwhelm system resources or trigger unexpected behavior in the application's parsing mechanisms. This lack of input sanitization creates a pathway for potential denial of service attacks or resource consumption issues that can impact system availability and performance.
The operational impact of CVE-2023-24604 extends beyond simple resource exhaustion, as it can potentially enable more sophisticated attack vectors within the broader security landscape. Attackers could leverage this vulnerability to consume excessive memory or processing power, leading to system instability or complete service disruption for legitimate users. The vulnerability aligns with CWE-129, which addresses improper validation of input length, and can be categorized under ATT&CK technique T1499.004 for resource exhaustion attacks. Organizations using affected versions of OX App Suite face significant risk of operational degradation, as the vulnerability can be exploited without requiring elevated privileges or complex attack chains, making it particularly dangerous in enterprise environments where calendar synchronization is critical for business operations.
Mitigation strategies for CVE-2023-24604 primarily focus on upgrading to the patched backend version 7.10.6-rev37 or later, which implements proper HTTP header length validation. System administrators should also consider implementing additional network-level controls such as proxy configurations that enforce header size limits, and monitoring for unusual header length patterns in network traffic. Organizations should conduct thorough vulnerability assessments to identify any systems running affected versions and implement comprehensive patch management procedures. The fix addresses the root cause by introducing proper input validation mechanisms that limit header sizes to reasonable values, preventing the exploitation of unlimited header data scenarios while maintaining compatibility with legitimate calendar data exchange protocols. Additionally, implementing rate limiting and connection timeout mechanisms can provide additional defense-in-depth measures against potential exploitation attempts.