Web Shells Exploit Unpatched Vulnerabilities for Persistent Access

Web shells are malicious scripts that attackers install on compromised web servers to maintain persistent remote access and execute commands. They typically exploit common web application vulnerabilities like SQL injection, cross-site scripting (XSS), remote file inclusion (RFI), and insecure file upload mechanisms to gain initial entry. Once deployed, these backdoors enable attackers to steal data, deface websites, and move laterally through networks. With over 16,000 publicly accessible web shell interfaces detected in 2024 alone, this threat demonstrates how unaddressed vulnerabilities can provide long-term access to critical systems.