CVE-2025-31324

CVE-2025-31324 is a critical (CVSS 9.8) unrestricted file upload flaw (CWE-434) in the Visual Composer Metadata Uploader component of SAP NetWeaver, which lacks proper authorization. An unauthenticated attacker can send crafted upload requests over the network to the Metadata Uploader endpoint and plant malicious executable binaries, such as webshells, on the host. Executing the uploaded files yields remote code execution with full impact on confidentiality, integrity, and availability, enabling system compromise, lateral movement, and ransomware deployment. Any organization running the affected SAP NetWeaver component is at risk, with the greatest exposure for instances reachable from the internet. Exploitation is confirmed in the wild: the flaw was added to CISA KEV on 2025-04-29, a public PoC exists, and researchers and media report active attacks, including by Chinese-linked actors deploying Golang-based implants on Linux systems and known ransomware use, often chained with CVE-2025-42999.

What to do: Apply SAP's patch for CVE-2025-31324 (released in the April 2025 security updates) and follow the vendor mitigation instructions per CISA KEV/BOD 22-01 requirements. As interim mitigation, restrict or disable the Visual Composer Metadata Uploader endpoint and ensure it is not reachable from the internet; also patch the related CVE-2025-42999 since the flaws are being chained. Check affected hosts for uploaded webshells, Golang-based implants, and signs of ransomware activity.