Catch situation where Regex flag fails (CTFd#1426)

* Catch an exception where a user supplied regex Flag can fail to parse * Starts on CTFd#1425
kolevv · May 20, 2020 · d3f8441 · d3f8441
1 parent ba887e8
commit d3f8441
Showing 1 changed file with 8 additions and 4 deletions.
diff --git a/CTFd/plugins/flags/__init__.py b/CTFd/plugins/flags/__init__.py
@@ -49,10 +49,14 @@ def compare(chal_key_obj, provided):
  saved = chal_key_obj.content
  data = chal_key_obj.data
 
- if data == "case_insensitive":
- res = re.match(saved, provided, re.IGNORECASE)
- else:
- res = re.match(saved, provided)
+ try:
+ if data == "case_insensitive":
+ res = re.match(saved, provided, re.IGNORECASE)
+ else:
+ res = re.match(saved, provided)
+ # TODO: this needs plugin improvements. See #1425.
+ except re.error:
+ return False
 
  return res and res.group() == provided