Wazuh: Path traversal in ip-customblock active response allows arbitrary file creation and deletion

Summary

Wazuh is an open-source security platform providing unified XDR and SIEM protection for endpoints and cloud workloads. The  ip-customblock  active response script contains a path traversal vulnerability that lets an attacker create or delete arbitrary files on the filesystem as root. The script builds a file path by concatenating the  srcip  field taken from alert JSON directly onto the fixed  /ipblock/  base directory, without validating that the value is a well-formed IP address. Because the extraction routine returns the raw string unchecked, an attacker who can trigger alert-matching log events with a crafted  srcip  containing  ../  sequences can escape the base directory. The block action opens the resulting path in append mode, creating an empty file at an arbitrary location, while the unblock action passes it to remove(), deleting an arbitrary file; since the active response daemon runs as root, this includes sensitive files such as system credentials and Wazuh configuration. Unlike the sibling scripts host-deny.c, default-firewall-drop.c, and firewalld-drop.c, which reject non-IP input via get_ip_version(), ip-customblock.c omits this validation. This issue is fixed in version 4.14.7.