Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3 and 2.3.1) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0, 2.12.3, and 2.3.1.

Pi-hole is a Linux network-level advertisement and Internet tracker blocking application. The Stored XSS exists in the Pi-hole Admin portal, which can be exploited by the malicious actor with the network access to DNS server. See the referenced GitHub security advisory for patch details.

Cross-site scripting (XSS) vulnerability in Citrix Web Interface 5.0, 5.1, and 5.3 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors, a different vulnerability than CVE-2007-6477 and CVE-2009-2454.