0.9.6

replace 0.9.5 which has only a partial fix

issue is now confirmed to affect all browsers

docs/source/changelog.md

@@ -9,6 +9,14 @@ command line for details.
 
 ## 0.9
 
+### [0.9.6] 2019-04-01
+
+JupyterHub 0.9.6 is a security release.
+
+- Fixes an Open Redirect vulnerability (CVE-2019-10255).
+
+JupyterHub 0.9.5 included a partial fix for this issue.
+
 ### [0.9.4] 2018-09-24
 
 JupyterHub 0.9.4 is a small bugfix release.
@@ -426,7 +434,8 @@ Fix removal of `/login` page in 0.4.0, breaking some OAuth providers.
 First preview release
 
 
-[Unreleased]: https://github.com/jupyterhub/jupyterhub/compare/0.9.4...HEAD
+[Unreleased]: https://github.com/jupyterhub/jupyterhub/compare/0.9.6...HEAD
+[0.9.6]: https://github.com/jupyterhub/jupyterhub/compare/0.9.4...0.9.6
 [0.9.4]: https://github.com/jupyterhub/jupyterhub/compare/0.9.3...0.9.4
 [0.9.3]: https://github.com/jupyterhub/jupyterhub/compare/0.9.2...0.9.3
 [0.9.2]: https://github.com/jupyterhub/jupyterhub/compare/0.9.1...0.9.2

hooks/post_push

@@ -12,8 +12,11 @@ function get_hub_version() {
   split=( ${hub_xyz//./ } )
   hub_xy="${split[0]}.${split[1]}"
   # add .dev on hub_xy so it's 1.0.dev
-  if [[ ! -z "${split[3]}" ]]; then
+  if [[ ! -z "${split[3]:-}" ]]; then
     hub_xy="${hub_xy}.${split[3]}"
+    latest=0
+  else
+    latest=1
   fi
 }
 
@@ -31,3 +34,11 @@ docker tag $DOCKER_REPO:$DOCKER_TAG $DOCKER_REPO:$hub_xy
 docker push $DOCKER_REPO:$hub_xy
 docker tag $ONBUILD:$DOCKER_TAG $ONBUILD:$hub_xy
 docker push $ONBUILD:$hub_xyz
+
+# if building a stable release, tag latest as well
+if [[ "$latest" == "1" ]]; then
+  docker tag $DOCKER_REPO:$DOCKER_TAG $DOCKER_REPO:latest
+  docker push $DOCKER_REPO:latest
+  docker tag $ONBUILD:$DOCKER_TAG $ONBUILD:latest
+  docker push $ONBUILD:latest
+fi

jupyterhub/_version.py

@@ -6,7 +6,7 @@
 version_info = (
     0,
     9,
-    4,
+    6,
     "",  # release (b1, rc1, or "" for final or dev)
     # "dev",  # dev or nothing
 )

jupyterhub/handlers/base.py

@@ -427,6 +427,8 @@ class BaseHandler(RequestHandler):
         - else: /hub/home
         """
         next_url = self.get_argument('next', default='')
+        # protect against some browsers' buggy handling of backslash as slash
+        next_url = next_url.replace('\\', '%5C')
         if (next_url + '/').startswith(
             (
                 '%s://%s/' % (self.request.protocol, self.request.host),
@@ -434,15 +436,23 @@ class BaseHandler(RequestHandler):
             )
         ):
             # treat absolute URLs for our host as absolute paths:
+            # below, redirects that aren't strictly paths
             parsed = urlparse(next_url)
             next_url = parsed.path
             if parsed.query:
                 next_url = next_url + '?' + parsed.query
-            if parsed.hash:
+            if parsed.fragment:
-                next_url = next_url + '#' + parsed.hash
+                next_url = next_url + '#' + parsed.fragment
-        if next_url and (urlparse(next_url).netloc or not next_url.startswith('/')):
+
+        # if it still has host info, it didn't match our above check for *this* host
+        if next_url and (
+            '://' in next_url
+            or next_url.startswith('//')
+            or not next_url.startswith('/')
+        ):
             self.log.warning("Disallowing redirect outside JupyterHub: %r", next_url)
             next_url = ''
+
         if next_url and next_url.startswith(url_path_join(self.base_url, 'user/')):
             # add /hub/ prefix, to ensure we redirect to the right user's server.
             # The next request will be handled by SpawnHandler,

jupyterhub/tests/test_pages.py

@@ -409,10 +409,13 @@ def test_login_strip(app):
         (False, '/has?query#andhash', '/has?query#andhash'),
 
         # next_url outside is not allowed
+        (False, 'relative/path', ''),
         (False, 'https://other.domain', ''),
         (False, 'ftp://other.domain', ''),
         (False, '//other.domain', ''),
-    ]
+        (False, '///other.domain/triple', ''),
+        (False, '\\\\other.domain/backslashes', ''),
+    ],
 )
 @pytest.mark.gen_test
 def test_login_redirect(app, running, next_url, location):
@@ -426,7 +429,7 @@ def test_login_redirect(app, running, next_url, location):
 
     url = 'login'
     if next_url:
-        if '//' not in next_url:
+        if '//' not in next_url and next_url.startswith('/'):
             next_url = ujoin(app.base_url, next_url, '')
         url = url_concat(url, dict(next=next_url))
 

singleuser/hooks/post_push

@@ -14,7 +14,7 @@ function get_hub_version() {
   split=( ${hub_xyz//./ } )
   hub_xy="${split[0]}.${split[1]}"
   # add .dev on hub_xy so it's 1.0.dev
-  if [[ ! -z "${split[3]}" ]]; then
+  if [[ ! -z "${split[3]:-}" ]]; then
     hub_xy="${hub_xy}.${split[3]}"
   fi
 }