CVE-2025-0728 in ThreadX NetX Duo
Summary
by MITRE • 02/21/2025
In NetX HTTP server functionality of Eclipse ThreadX NetX Duo before version 6.4.2, an attacker can cause an integer underflow and a subsequent denial of service by writing a very large file, by specially crafted packets with Content-Length smaller than the data request size. A possible workaround is to disable HTTP PUT support.
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Analysis
by VulDB Data Team • 07/31/2025
The vulnerability identified as CVE-2025-0728 affects the NetX HTTP server functionality within Eclipse ThreadX NetX Duo versions prior to 6.4.2. This issue represents a critical security flaw that stems from improper handling of HTTP request processing, specifically in how the system manages file upload operations and content length validation. The vulnerability resides in the server's implementation of HTTP PUT methods and demonstrates a classic example of inadequate input validation that can lead to system instability and service disruption. The affected component operates within embedded systems and networked devices that rely on ThreadX for real-time operating system functionality, making this vulnerability particularly concerning for industrial control systems and IoT deployments.
The technical flaw manifests as an integer underflow condition that occurs when processing HTTP PUT requests with malformed Content-Length headers. An attacker can exploit this by crafting specially designed packets where the Content-Length value is significantly smaller than the actual data being transmitted during the request. This discrepancy causes the server's internal counter to underflow, resulting in unpredictable behavior and ultimately leading to a complete denial of service condition. The vulnerability follows the CWE-190 pattern of integer overflow/underflow, specifically targeting the arithmetic operations that manage file transfer sizes and buffer allocations. The underlying issue demonstrates poor error handling and insufficient bounds checking in the HTTP server's request parsing logic, which allows malicious input to cascade into system-level failures.
The operational impact of this vulnerability extends beyond simple service interruption to potentially compromise the availability of critical networked systems. When exploited, the integer underflow causes the HTTP server to crash or become unresponsive, rendering the entire service inaccessible to legitimate users and potentially affecting other system functions that depend on network connectivity. This denial of service condition can be particularly damaging in embedded environments where system uptime is critical, such as in industrial automation, medical devices, or network infrastructure equipment. The vulnerability affects systems that rely on HTTP PUT functionality for file uploads, which is commonly used in configuration management, firmware updates, and data synchronization operations. From an attack perspective, this vulnerability aligns with ATT&CK technique T1499.004 for network denial of service, as it specifically targets the availability of network services through manipulation of HTTP protocol elements.
Mitigation strategies for CVE-2025-0728 focus on both immediate defensive measures and long-term architectural improvements. The recommended workaround of disabling HTTP PUT support provides a temporary solution that eliminates the attack surface associated with this specific vulnerability while allowing systems to maintain basic HTTP functionality. Organizations should also consider implementing network-level protections such as firewalls and intrusion detection systems that can monitor for suspicious HTTP packet patterns and Content-Length anomalies. The most effective long-term solution involves upgrading to Eclipse ThreadX NetX Duo version 6.4.2 or later, which includes proper bounds checking and integer overflow protection mechanisms. Security teams should also implement regular vulnerability assessments and network monitoring to detect potential exploitation attempts, as well as establish incident response procedures that can quickly address service disruption events caused by similar vulnerabilities. Additionally, developers should follow secure coding practices that emphasize input validation and proper error handling, particularly when dealing with network protocol implementations that process user-supplied data.