Microsoft: Critical GoAnywhere Bug Exploited in Medusa Ransomware Camp

Fortinet FortiClient EMS — the central management server for FortiClient endpoint deployments — contains a SQL injection flaw (CWE-89) in versions 7.0.1 through 7.0.10 and 7.2.0 through 7.2.2. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N) shows it can be triggered remotely with no credentials and no user interaction: an unauthenticated attacker sends specially crafted packets to the vulnerable management server and can execute unauthorized code or commands. Successful exploitation effectively yields remote code execution on the EMS server and access to its database, enabling follow-on actions such as credential theft, abuse of endpoint management functions, and ransomware deployment. Any organization running the affected EMS versions is exposed, especially where the management server is reachable from the internet. Exploitation is confirmed in the wild: CISA added the bug to the KEV catalog on 2024-03-25 with known ransomware use, and EPSS assigns a ~98.4% probability of exploitation within 30 days (100th percentile).

Do: Upgrade FortiClient EMS to the fixed releases per Fortinet's advisory for this CVE (7.2.3 and 7.0.11 or later, i.e., beyond the 7.2.2 and 7.0.10 affected ranges); the CISA KEV required action is to apply vendor mitigations or discontinue use if mitigations are unavailable. Until patched, limit exposure of the EMS web interface to untrusted networks and hunt for signs of compromise — anomalous requests to the management console, unexpected database or admin activity, and follow-on ransomware behavior — since exploitation with known ransomware use is confirmed.

ConnectWise ScreenConnect (ConnectWise Control), a widely used remote-access and remote-monitoring tool, contains an authentication bypass (CWE-288) in its management interface. An attacker needs only network access to the management interface to trigger the flaw, with no valid credentials or user interaction required. A successful attacker gains administrative control of the ScreenConnect server by creating a new administrator-level account, providing a foothold that has already been used in ransomware campaigns against downstream managed environments. Any organization running ConnectWise ScreenConnect is affected, especially managed service providers and IT teams whose management interface is reachable from the internet; the source data specifies affected products but no version ranges. Exploitation is confirmed and urgent: CISA added the flaw to the KEV on 2024-02-22 with known ransomware use, EPSS assigns a 100% probability of exploitation within 30 days, and ConnectWise warned that no patch was available at the time of disclosure.

Do: Follow ConnectWise's instructions immediately: no patch existed at disclosure, so apply the vendor's mitigations or, per the CISA KEV required action, restrict internet exposure of the management interface or discontinue use until mitigations are available, then upgrade to the vendor's patched release as soon as it ships. Audit ScreenConnect servers for unexpectedly created administrator-level accounts and unusual remote sessions, which are the attack's artifacts. Prioritize any instance whose management interface is reachable from the internet, given confirmed in-the-wild exploitation and known ransomware use.

CVE-2025-10035 is a critical (CVSS 9.8) deserialization-of-untrusted-data flaw (CWE-502) in the License Servlet of Fortra GoAnywhere Managed File Transfer (MFT). It is triggered when the servlet processes a license response carrying a validly forged signature, causing it to deserialize an arbitrary attacker-controlled object; the CVSS vector indicates the attack is network-based and requires no privileges or user interaction. Successful exploitation can lead to command injection (CWE-77), effectively giving an attacker command execution on the MFT server and access to the files and credentials that flow through it. Any organization running GoAnywhere MFT, which is commonly deployed as a central file-transfer hub, is affected, although specific affected/fixed version ranges are not provided in the available data. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV catalog on 2025-09-29 with known ransomware use, Microsoft attributes attacks to the Storm-1175 ransomware affiliate (Medusa, now reportedly replaced by StormEncryptor), and EPSS assigns a 99.8% probability of exploitation within 30 days.

Do: Apply mitigations or patches per Fortra's vendor instructions immediately, as this is a KEV entry carrying BOD 22-01 requirements for federal agencies (patch or discontinue use if mitigations are unavailable). Because a ransomware affiliate (Storm-1175, using Medusa/StormEncryptor) is actively exploiting it, hunt for compromise: review License Servlet traffic and logs for forged license responses, check for unexpected processes or new accounts, and look for signs of lateral movement. Until patched, restrict or remove internet exposure of GoAnywhere MFT admin and license interfaces.