CVE-2025-30642 is a vulnerability classified under CWE-59 (Improper Link Resolution Before File Access) affecting Trend Micro Deep Security version 20.0 agents. The issue arises from the software's improper handling of symbolic links (symlinks) or other link types before accessing files. Specifically, a local attacker who already has the ability to execute low-privileged code on the target system can exploit this flaw to cause a denial of service (DoS) condition. The vulnerability does not allow for privilege escalation, data confidentiality breach, or integrity compromise directly, but it can disrupt the availability of the Deep Security agent, potentially disabling critical security monitoring and protection functions. The CVSS v3.1 base score is 5.5 (medium severity), with vector AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating that the attack requires local access with low privileges, no user interaction, and results in high impact on availability only. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability is limited to version 20.0 of the product, which is widely used in enterprise environments for endpoint and server protection. The improper link resolution could be exploited by creating malicious symlinks that redirect the Deep Security agent's file operations to unintended locations, causing the agent to fail or crash, thus leading to service disruption.

For European organizations, the primary impact of this vulnerability is the potential disruption of security services provided by Trend Micro Deep Security agents. Since these agents are deployed to protect critical infrastructure, servers, and endpoints, a successful DoS attack could leave systems unmonitored and vulnerable to other threats. This could be particularly damaging in sectors with high security requirements such as finance, healthcare, energy, and government institutions. The inability of the agent to function properly may delay detection and response to other attacks, increasing the risk of data breaches or operational disruptions. However, since exploitation requires local code execution with low privileges, the attacker must have already compromised the system to some extent, limiting the initial attack vector. Nonetheless, the vulnerability could be leveraged as part of a multi-stage attack to degrade defenses. The medium severity rating reflects that while confidentiality and integrity are not directly impacted, availability loss of security controls can have cascading effects on overall organizational security posture.

1. Restrict local access: Limit the ability of users and processes to execute code locally on systems running Trend Micro Deep Security agents, using strict access controls and application whitelisting. 2. Monitor for suspicious symlink activity: Implement file system monitoring to detect unusual creation or manipulation of symbolic links, especially in directories accessed by the Deep Security agent. 3. Harden agent environment: Run the Deep Security agent with the least privileges necessary and ensure the underlying OS is hardened against local privilege escalation. 4. Network segmentation: Isolate critical systems running the agent to reduce the risk of local code execution by unauthorized users. 5. Apply vendor updates promptly: Although no patch links are currently available, monitor Trend Micro advisories closely and apply patches as soon as they are released. 6. Incident response readiness: Prepare to quickly detect and respond to agent failures or DoS symptoms to restore security monitoring capabilities. 7. Use complementary security controls: Employ additional endpoint detection and response (EDR) tools to compensate for potential agent downtime.