CVE-2023-40044

CVE-2023-40044 is a critical vulnerability in the WS_FTP Server, a popular secure file transfer solution developed by Progress Software. This flaw, identified as a .NET deserialization vulnerability in the Ad Hoc Transfer Module, was disclosed alongside another vulnerability (CVE-2023-42657) and has received the highest possible CVSS rating of 10. The vulnerabilities were uncovered following a recent hack on Progress Software's MOVEit file-sharing tool. Rapid7 researchers reported "mass exploitation" of these recently disclosed flaws across multiple instances of WS_FTP Server software beginning on September 30, 2023. The critical nature of CVE-2023-40044, coupled with the availability of proof-of-concept (PoC) code, made it an attractive target for attackers, leading to widespread exploitation. In response to the discovery and subsequent exploitation of these vulnerabilities, Progress Software has released security updates to address both CVE-2023-40044 and CVE-2023-42657 in their WS_FTP Server software. Users of the software are strongly encouraged to apply these updates immediately to mitigate the risk posed by these critical vulnerabilities.