diff options
Diffstat (limited to 'Mailman/CSRFcheck.py')
| -rw-r--r-- | Mailman/CSRFcheck.py | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/Mailman/CSRFcheck.py b/Mailman/CSRFcheck.py index a1e78d98..24e3e11b 100644 --- a/Mailman/CSRFcheck.py +++ b/Mailman/CSRFcheck.py @@ -18,11 +18,13 @@ """ Cross-Site Request Forgery checker """ import time +import urllib import marshal import binascii from Mailman import mm_cfg -from Mailman.Utils import sha_new +from Mailman.Logging.Syslog import syslog +from Mailman.Utils import UnobscureEmail, sha_new keydict = { 'user': mm_cfg.AuthUser, @@ -37,6 +39,10 @@ keydict = { def csrf_token(mlist, contexts, user=None): """ create token by mailman cookie generation algorithm """ + if user: + # Unmunge a munged email address. + user = UnobscureEmail(urllib.unquote(user)) + for context in contexts: key, secret = mlist.AuthContextInfo(context, user) if key: @@ -49,9 +55,8 @@ def csrf_token(mlist, contexts, user=None): token = binascii.hexlify(marshal.dumps((issued, keymac))) return token -def csrf_check(mlist, token): +def csrf_check(mlist, token, options_user=None): """ check token by mailman cookie validation algorithm """ - try: issued, keymac = marshal.loads(binascii.unhexlify(token)) key, received_mac = keymac.split(':', 1) @@ -62,6 +67,17 @@ def csrf_check(mlist, token): key, user = key.split('+', 1) else: user = None + if user: + # This is for CVE-2021-42097. The token is a user token because + # of the fix for CVE-2021-42096 but it must match the user for + # whom the options page is requested. + raw_user = UnobscureEmail(urllib.unquote(user)) + if options_user and options_user != raw_user: + syslog('mischief', + 'Form for user %s submitted with CSRF token ' + 'issued for %s.', + options_user, raw_user) + return False context = keydict.get(key) key, secret = mlist.AuthContextInfo(context, user) assert key |