Apache Struts 2.0.0 through 2.3.24.1 does not properly cache method references when used with OGNL before 3.0.12, which allows remote attackers to cause a denial of service (block access to a web site) via unspecified vectors.

Apache Struts 2.x before 2.3.25 does not sanitize text in the Locale object constructed by I18NInterceptor, which might allow remote attackers to conduct cross-site scripting (XSS) attacks via unspecified vectors involving language display.

Apache Struts 2.0.0 through 2.3.x before 2.3.20 uses predictable <s:token/> values, which allows remote attackers to bypass the CSRF protection mechanism.

Apache Struts 2.0.0 through 2.3.15.1 allows remote attackers to bypass access controls via a crafted action: prefix.

Multiple open redirect vulnerabilities in Apache Struts 2.0.0 through 2.3.15 allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in a parameter using the (1) redirect: or (2) redirectAction: prefix.

OGNL provides, among other features, extensive expression evaluation capabilities. This vulnerability allows a malicious user to bypass the '#'-usage protection built into the ParametersInterceptor, thus being able to manipulate server side context objects. This behavior was already addressed in S2-003, but it turned out that the resulting fix based on whitelisting acceptable parameter names closed the vulnerability only partially.