Active Exploitation of Unpatched LFI Vulnerability in Gladinet CentreStack and TrioFox (CVE-2025-11371)

Attackers are actively exploiting a zero-day vulnerability, CVE-2025-11371, in Gladinet CentreStack and TrioFox file-sharing and remote access platforms. This vulnerability is an unauthenticated local file inclusion (LFI) flaw that allows threat actors to access sensitive system files, including the application’s Web.config file. By retrieving the machine key from this configuration file, attackers can leverage a previously patched vulnerability, CVE-2025-30406, to achieve remote code execution (RCE) through ViewState deserialization attacks. Huntress, a cybersecurity firm, first detected exploitation of this flaw on September 26-27, 2025, and has confirmed that at least three customers have been impacted so far. The vulnerability affects all versions of CentreStack and TrioFox up to and including 16.7.10368.56560, and there is currently no official patch available from Gladinet. Both self-hosted and cloud-hosted deployments of these platforms are at risk, as the flaw impacts default installations and configurations. The exploitation chain involves using the LFI to extract the machine key, which is then used to craft malicious ViewState payloads that bypass integrity checks and enable arbitrary code execution on the server. Notably, Huntress observed successful exploitation even on systems that had already patched CVE-2025-30406, indicating that the previous fix was insufficient to fully mitigate the risk. In response, Huntress and other security experts recommend disabling the "temp" handler within the UploadDownloadProxy Web.config file as an immediate mitigation, though this may impact some platform functionality. Gladinet has acknowledged the vulnerability and its active exploitation but has not yet released a patch, urging customers to implement the recommended mitigations. The affected products are widely used by managed service providers, small businesses, and enterprises for secure file access and sharing, increasing the potential impact of this vulnerability. Attackers exploiting this flaw can gain full control over affected servers, leading to data theft, lateral movement, or further compromise of organizational networks. Security researchers are withholding some technical details to prevent further exploitation while a patch is developed. Organizations using CentreStack or TrioFox should urgently review their configurations and apply the recommended mitigations to reduce exposure. The incident highlights the risks associated with chained vulnerabilities and the importance of defense-in-depth strategies. Ongoing monitoring and threat detection are advised until a permanent fix is available. The situation remains fluid, with active exploitation continuing and the vendor working on a security update.