Illegal access crash from if-modified-since header

lib/ecstatic.js

@@ -276,9 +276,20 @@ var ecstatic = module.exports = function (dir, options) {
         return false;
       }
 
-      // If any of the headers provided don't match, then don't return 304
-      if (modifiedSince && (new Date(Date.parse(modifiedSince))) < stat.mtime) {
-        return false;
+      // Catch "illegal access" dates that will crash v8
+      if (modifiedSince) {
+        try {
+          var modifiedDate = new Date(Date.parse(modifiedSince));
+        }
+        catch (err) { return false }
+
+        if (modifiedDate.toString() === 'Invalid Date') {
+          return false;
+        }
+        // If any of the headers provided don't match, then don't return 304
+        if (modifiedDate < stat.mtime) {
+          return false;
+        }
       }
 
       if (clientEtag) {

test/illegal-access-date.js

@@ -0,0 +1,24 @@
+var test = require('tap').test,
+    ecstatic = require('../lib/ecstatic'),
+    http = require('http'),
+    path = require('path'),
+    request = require('request');
+
+test('if-modified-since illegal access date', function (t) {
+  var dir = path.join(__dirname, 'public');
+  var server = http.createServer(ecstatic(dir))
+
+  t.plan(2);
+
+  server.listen(0, function () {
+    var opts = {
+      url: 'http://localhost:' + server.address().port + '/a.txt',
+      headers: { 'if-modified-since': '275760-09-24' }
+    };
+    request.get(opts, function (err, res, body) {
+      t.ifError(err);
+      t.equal(res.statusCode, 200);
+      server.close(function() { t.end(); });
+    });
+  });
+});