===================================================================
RCS file: /cvs/mandoc/cgi.c,v
retrieving revision 1.75
retrieving revision 1.77
diff -u -p -r1.75 -r1.77
--- mandoc/cgi.c	2014/07/18 19:03:39	1.75
+++ mandoc/cgi.c	2014/07/19 13:15:11	1.77
@@ -1,4 +1,4 @@
-/*	$Id: cgi.c,v 1.75 2014/07/18 19:03:39 schwarze Exp $ */
+/*	$Id: cgi.c,v 1.77 2014/07/19 13:15:11 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014 Ingo Schwarze <schwarze@usta.de>
@@ -466,6 +466,32 @@ resp_searchform(const struct req *req)
 	puts("<!-- End search form. //-->");
 }
 
+static int
+validate_manpath(const struct req *req, const char* manpath)
+{
+	size_t	 i;
+
+	if ( ! strcmp(manpath, "mandoc"))
+		return(1);
+
+	for (i = 0; i < req->psz; i++)
+		if ( ! strcmp(manpath, req->p[i]))
+			return(1);
+
+	return(0);
+}
+
+static int
+validate_filename(const char *file)
+{
+
+	if ('.' == file[0] && '/' == file[1])
+		file += 2;
+
+	return ( ! (strstr(file, "../") || strstr(file, "/..") ||
+	    (strncmp(file, "man", 3) && strncmp(file, "cat", 3))));
+}
+
 static void
 pg_index(const struct req *req)
 {
@@ -523,6 +549,15 @@ pg_searchres(const struct req *req, struct manpage *r,
 	int		 prio, priouse;
 	char		 sec;
 
+	for (i = 0; i < sz; i++) {
+		if (validate_filename(r[i].file))
+			continue;
+		fprintf(stderr, "invalid filename %s in %s database\n",
+		    r[i].file, req->q.manpath);
+		pg_error_internal();
+		return;
+	}
+
 	if (1 == sz) {
 		/*
 		 * If we have just one result, then jump there now
@@ -777,7 +812,8 @@ format(const struct req *req, const char *file)
 static void
 resp_show(const struct req *req, const char *file)
 {
-	if ('.' == file[0] || '/' == file[1])
+
+	if ('.' == file[0] && '/' == file[1])
 		file += 2;
 
 	if ('c' == *file)
@@ -798,6 +834,12 @@ pg_show(const struct req *req, const char *path)
 	} 
 	*sub++ = '\0';
 
+	if ( ! validate_manpath(req, path)) {
+		pg_error_badrequest(
+		    "You specified an invalid manpath.");
+		return;
+	}
+
 	/*
 	 * Begin by chdir()ing into the manpath.
 	 * This way we can pick up the database files, which are
@@ -805,8 +847,15 @@ pg_show(const struct req *req, const char *path)
 	 */
 
 	if (-1 == chdir(path)) {
+		fprintf(stderr, "chdir %s: %s\n",
+		    path, strerror(errno));
+		pg_error_internal();
+		return;
+	}
+
+	if ( ! validate_filename(sub)) {
 		pg_error_badrequest(
-		    "You specified an invalid manpath.");
+		    "You specified an invalid manual file.");
 		return;
 	}
 
@@ -834,8 +883,9 @@ pg_search(const struct req *req)
 	 */
 
 	if (-1 == (chdir(req->q.manpath))) {
-		pg_error_badrequest(
-		    "You specified an invalid manpath.");
+		fprintf(stderr, "chdir %s: %s\n",
+		    req->q.manpath, strerror(errno));
+		pg_error_internal();
 		return;
 	}
 
@@ -926,6 +976,12 @@ main(void)
 
 	if (NULL != (querystring = getenv("QUERY_STRING")))
 		http_parse(&req, querystring);
+
+	if ( ! validate_manpath(&req, req.q.manpath)) {
+		pg_error_badrequest(
+		    "You specified an invalid manpath.");
+		return(EXIT_FAILURE);
+	}
 
 	/* Dispatch to the three different pages. */