U.S. CISA adds Gladinet CentreStack and ZTA Microsoft Windows CLFS Driver flaws to its Known Exploited Vulnerabilities catalog

CVE-2025-29824 is a use-after-free flaw (CWE-416) in the Windows Common Log File System (CLFS) kernel driver, scored 7.8 (High) with a local attack vector, low privileges required, and no user interaction. An authorized local attacker can trigger it by interacting with CLFS-managed log files in a way that references freed kernel memory. Successful exploitation elevates the attacker's local privileges, typically to SYSTEM, providing full control of the host that can be chained into ransomware deployment or lateral movement. Any unpatched system running the listed Windows 10, Windows 11, or Windows Server versions is affected. The flaw was exploited as a zero-day — reportedly by Play ransomware — before Microsoft shipped fixes in the April 2025 Patch Tuesday release; it was added to CISA's KEV catalog on 2025-04-08 with known ransomware use, and EPSS estimates a 13.9% probability of continued exploitation over 30 days (96th percentile).

Do: Apply Microsoft's April 2025 Patch Tuesday security updates for your Windows version immediately — the vendor update is the only complete fix, and the flaw is on the KEV list with known ransomware use, so prioritize servers and endpoints used by privileged users. Until patched, limit untrusted local code execution and review hosts for post-exploitation privilege escalation; public detection and mitigation scripts (e.g., Vicarius) are available to help hunt for exploitation. Federal agencies must apply the vendor mitigations per BOD 22-01 deadlines or discontinue use of affected versions.

Gladinet CentreStack (and, per CISA, the companion product Triofox) ships with a hard-coded ASP.NET machineKey in the portal's web.config, which is used to protect ViewState and similar serialized data. An attacker who knows this fixed key can craft a serialized payload and submit it to the network-facing portal, where server-side deserialization executes it, yielding unauthenticated remote code execution (CVSS 9.8, no privileges or user interaction required). Successful RCE gives attackers full control of the file-sharing server (high confidentiality, integrity and availability impact); public reporting indicates attackers have abused the flaw to gain unauthorized access and install remote access tools. Anyone running the affected CentreStack builds is exposed, with self-hosted deployments at SMBs and MSP-hosted environments the typical footprint. The flaw was exploited in the wild in March 2025, was added to CISA's Known Exploited Vulnerabilities catalog on 2025-04-08, and carries an EPSS of 94.3% (100th percentile).

Do: Upgrade CentreStack to 16.4.10315.56368 or later, and apply the equivalent vendor fix for Triofox; as an interim mitigation, administrators can delete the hard-coded machineKey defined in portal\web.config so it is regenerated. Because the flaw is actively exploited, review portals for signs of compromise (unexpected accounts, unfamiliar processes or remote access tools) and, for federal agencies, follow the applicable BOD 22-01 required actions.