An information disclosure of the content of restricted files WEB-INF and META-INF via filter mechanism was reported. Servlet filter restriction mechanism is enforced by two code checks:

if (path.startsWith("/META-INF") || path.startsWith("META-INF") || path.startsWith("/WEB-INF") || path.startsWith("WEB-INF")) { return false; }

private boolean isForbiddenPath(String path) { return path.equalsIgnoreCase("/meta-inf/") || path.regionMatches(true, 0, "/web-inf/", 0, "/web-inf/".length()); }

which can be bypassed using lower case and adding meaningless character to path.