1 files changed, 41 insertions, 4 deletions

diff --git a/subversion/libsvn_ra_svn/client.c b/subversion/libsvn_ra_svn/client.c
index 9ea59d20e147..a4939ab2ad53 100644
--- a/subversion/libsvn_ra_svn/client.c
+++ b/subversion/libsvn_ra_svn/client.c
@@ -46,6 +46,7 @@
 #include "svn_props.h"
 #include "svn_mergeinfo.h"
 #include "svn_version.h"
+#include "svn_ctype.h"
 
 #include "svn_private_config.h"
 
@@ -396,7 +397,7 @@ static svn_error_t *find_tunnel_agent(const char *tunnel,
        * versions have it too. If the user is using some other ssh
        * implementation that doesn't accept it, they can override it
        * in the [tunnels] section of the config. */
-      val = "$SVN_SSH ssh -q";
+      val = "$SVN_SSH ssh -q --";
     }
 
   if (!val || !*val)
@@ -441,7 +442,7 @@ static svn_error_t *find_tunnel_agent(const char *tunnel,
   for (n = 0; cmd_argv[n] != NULL; n++)
     argv[n] = cmd_argv[n];
 
-  argv[n++] = svn_path_uri_decode(hostinfo, pool);
+  argv[n++] = hostinfo;
   argv[n++] = "svnserve";
   argv[n++] = "-t";
   argv[n] = NULL;
@@ -802,6 +803,32 @@ ra_svn_get_schemes(apr_pool_t *pool)
 }
 
 
+/* A simple whitelist to ensure the following are valid:
+ *   user@server
+ *   [::1]:22
+ *   server-name
+ *   server_name
+ *   127.0.0.1
+ * with an extra restriction that a leading '-' is invalid.
+ */
+static svn_boolean_t
+is_valid_hostinfo(const char *hostinfo)
+{
+  const char *p = hostinfo;
+
+  if (p[0] == '-')
+    return FALSE;
+
+  while (*p)
+    {
+      if (!svn_ctype_isalnum(*p) && !strchr(":.-_[]@", *p))
+        return FALSE;
+
+      ++p;
+    }
+
+  return TRUE;
+}
 
 static svn_error_t *ra_svn_open(svn_ra_session_t *session,
                                 const char **corrected_url,
@@ -835,8 +862,18 @@ static svn_error_t *ra_svn_open(svn_ra_session_t *session,
           || (callbacks->check_tunnel_func && callbacks->open_tunnel_func
               && !callbacks->check_tunnel_func(callbacks->tunnel_baton,
                                                tunnel))))
-    SVN_ERR(find_tunnel_agent(tunnel, uri.hostinfo, &tunnel_argv, config,
-                              result_pool));
+    {
+      const char *decoded_hostinfo;
+
+      decoded_hostinfo = svn_path_uri_decode(uri.hostinfo, result_pool);
+
+      if (!is_valid_hostinfo(decoded_hostinfo))
+        return svn_error_createf(SVN_ERR_BAD_URL, NULL, _("Invalid host '%s'"),
+                                 uri.hostinfo);
+
+      SVN_ERR(find_tunnel_agent(tunnel, decoded_hostinfo, &tunnel_argv,
+                                config, result_pool));
+    }
   else
     tunnel_argv = NULL;