CVE-2025-63829 identifies a vulnerability in eProsima Fast-DDS version 3.3 and earlier, specifically an infinite loop caused by an integer overflow in the Time_t::fraction() function. Fast-DDS is a middleware implementation of the Data Distribution Service (DDS) standard, widely used in real-time distributed systems such as robotics, automotive, aerospace, and industrial automation. The vulnerability stems from improper integer handling that leads to an infinite loop when processing time fractions, classified under CWE-835, which involves loops with unreachable exit conditions. This infinite loop can cause the affected process to hang indefinitely, potentially leading to resource exhaustion or denial of service. The CVSS 3.1 base score is 5.3 (medium), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and limited confidentiality impact (C:L), with no impact on integrity or availability. No known exploits have been reported, and no patches are currently available, increasing the urgency for monitoring and mitigation. The vulnerability affects all deployments of Fast-DDS v3.3 and earlier, which are common in European industries relying on real-time data exchange. Exploitation requires only network access to the Fast-DDS service, making exposed deployments vulnerable to remote attackers.

For European organizations, the primary impact of CVE-2025-63829 is potential denial of service or resource exhaustion due to the infinite loop in Fast-DDS processes. This can disrupt critical real-time communication in sectors such as automotive manufacturing, aerospace control systems, robotics, and industrial automation, where Fast-DDS is commonly deployed. Although the vulnerability does not directly compromise data integrity or availability, the infinite loop can degrade system responsiveness or cause service interruptions, impacting operational continuity. Confidentiality impact is limited but present, as the CVSS vector indicates some potential information exposure. Organizations relying on Fast-DDS for safety-critical or time-sensitive applications may face increased operational risks, including delays or failures in automated processes. The lack of patches and known exploits means the threat is currently theoretical but could become practical if attackers develop exploits. European entities with exposed Fast-DDS services on public or poorly segmented networks are at higher risk.

1. Monitor network traffic and system resource usage for signs of abnormal CPU or memory consumption that could indicate exploitation attempts. 2. Restrict network access to Fast-DDS services using firewalls and network segmentation to limit exposure to untrusted networks. 3. Implement strict access controls and isolate Fast-DDS nodes within secure network zones. 4. Engage with eProsima or relevant vendors to obtain updates or patches as soon as they become available and apply them promptly. 5. Conduct code reviews and testing for integer overflow and loop conditions in custom implementations or integrations of Fast-DDS. 6. Use runtime protections such as watchdog timers or process supervisors to detect and recover from infinite loops or hangs. 7. Educate operational technology and security teams about this vulnerability to ensure rapid response if exploitation is suspected. 8. Consider deploying intrusion detection systems tuned to detect anomalous behavior related to Fast-DDS communications.