X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=plugins%2Fmod_http_files.lua;h=3b60249559c6e7e42bee94699d0f14ba122f7c4b;hb=ce3e9d066610d7e15e31263f59fa597eca079064;hp=7c503c826cde665db207d75f1020ab092722e6d8;hpb=a14deb1f4521c0dd3a1e062c521ba71c54bafc75;p=prosody.git

diff --git a/plugins/mod_http_files.lua b/plugins/mod_http_files.lua
index 7c503c82..3b602495 100644
--- a/plugins/mod_http_files.lua
+++ b/plugins/mod_http_files.lua
@@ -49,6 +49,38 @@ if not mime_map then
 	end
 end
 
+local forbidden_chars_pattern = "[/%z]";
+if prosody.platform == "windows" then
+	forbidden_chars_pattern = "[/%z\001-\031\127\"*:<>?|]"
+end
+
+local urldecode = require "util.http".urldecode;
+function sanitize_path(path)
+	if not path then return end
+	local out = {};
+
+	local c = 0;
+	for component in path:gmatch("([^/]+)") do
+		component = urldecode(component);
+		if component:find(forbidden_chars_pattern) then
+			return nil;
+		elseif component == ".." then
+			if c <= 0 then
+				return nil;
+			end
+			out[c] = nil;
+			c = c - 1;
+		elseif component ~= "." then
+			c = c + 1;
+			out[c] = component;
+		end
+	end
+	if path:sub(-1,-1) == "/" then
+		out[c+1] = "";
+	end
+	return "/"..table.concat(out, "/");
+end
+
 local cache = setmetatable({}, { __mode = "kv" }); -- Let the garbage collector have it if it wants to.
 
 function serve(opts)
@@ -60,8 +92,13 @@ function serve(opts)
 	local directory_index = opts.directory_index;
 	local function serve_file(event, path)
 		local request, response = event.request, event.response;
-		local orig_path = request.path;
-		local full_path = base_path .. (path and "/"..path or ""):gsub("/", path_sep);
+		local sanitized_path = sanitize_path(path);
+		if path and not sanitized_path then
+			return 400;
+		end
+		path = sanitized_path;
+		local orig_path = sanitize_path(request.path);
+		local full_path = base_path .. (path or ""):gsub("/", path_sep);
 		local attr = stat(full_path:match("^.*[^\\/]")); -- Strip trailing path separator because Windows
 		if not attr then
 			return 404;