cookie accepts cookie name, path, and domain with out of bounds characters

Impact

The cookie name could be used to set other fields of the cookie, resulting in an unexpected cookie value. For example, serialize("userName=<script>alert('XSS3')</script>; Max-Age=2592000; a", value) would result in "userName=<script>alert('XSS3')</script>; Max-Age=2592000; a=test", setting userName cookie to <script> and ignoring value.

A similar escape can be used for path and domain, which could be abused to alter other fields of the cookie.

Patches

Upgrade to 0.7.0, which updates the validation for name, path, and domain.

Workarounds

Avoid passing untrusted or arbitrary values for these fields, ensure they are set by the application instead of user input.

References

• https://github.com/jshttp/cookie/pull/167