CVE-2025-9649 is a security vulnerability identified in the appneta tcpreplay tool, specifically version 4.5.1. The vulnerability exists in the function calc_sleep_time within the send_packets.c source file. The issue arises due to a divide-by-zero error caused by improper handling of input values or internal calculations. This flaw can lead to undefined behavior, potentially causing the application to crash or behave unpredictably. The vulnerability requires local access to the system, meaning an attacker must have some level of local privileges to exploit it. There is no need for user interaction, and no network-based exploitation is possible directly. The vendor has acknowledged the issue and confirmed that the vulnerability is reproducible in version 4.5.1 but fixed in version 4.5.3-beta3. The CVSS v4.0 score is 4.8, indicating a medium severity level, with the attack vector being local (AV:L), low complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and limited impact on confidentiality, integrity, and availability. The vulnerability does not affect system components beyond the tcpreplay tool itself and does not propagate or escalate privileges by itself. The exploit has been publicly disclosed, but there are no known exploits in the wild at this time. The primary risk is denial of service or application crash, which could disrupt network traffic replay operations or testing environments relying on tcpreplay.

For European organizations, the impact of this vulnerability is generally limited to environments where appneta tcpreplay is used, typically in network testing, simulation, or forensic analysis contexts. Organizations relying on tcpreplay for network performance testing or security research could experience service interruptions or crashes if the vulnerability is exploited locally. Since exploitation requires local access, the threat is primarily to internal users or attackers who have already compromised a system. This reduces the risk of widespread external attacks but highlights the importance of internal security controls. Disruption of network testing could delay incident response or network troubleshooting activities, potentially impacting operational efficiency. However, the vulnerability does not directly lead to data breaches or remote code execution, limiting its broader impact on confidentiality or integrity. European entities with strong internal access controls and patch management practices will be less affected, but organizations with less mature endpoint security or insider threat risks should prioritize remediation.

To mitigate this vulnerability, European organizations should upgrade appneta tcpreplay to version 4.5.3-beta3 or later, where the divide-by-zero issue is resolved. Since the vulnerability requires local access, enforcing strict access controls on systems running tcpreplay is critical. Limit the number of users with local login privileges and monitor for unusual activity on these hosts. Implement application whitelisting and endpoint detection to identify attempts to exploit the flaw. Regularly audit and update network testing tools to ensure they are running supported, patched versions. Additionally, consider isolating systems used for network replay and testing from production environments to reduce the risk of lateral movement or impact on critical infrastructure. Document and train staff on secure usage of tcpreplay and related tools to minimize accidental misuse that could trigger the vulnerability.