From a306294cf9e4d4a4ded2c840f9a1ce8ba412b6a7 Mon Sep 17 00:00:00 2001 From: Mark Sapiro Date: Tue, 30 Nov 2021 09:50:49 -0800 Subject: Block CSRF attack against admin or admindb pages. --- Mailman/CSRFcheck.py | 17 +++++++++++++++-- Mailman/Cgi/admin.py | 3 ++- Mailman/Cgi/admindb.py | 3 ++- Mailman/Cgi/edithtml.py | 3 ++- NEWS | 7 ++++++- 5 files changed, 27 insertions(+), 6 deletions(-) diff --git a/Mailman/CSRFcheck.py b/Mailman/CSRFcheck.py index 4505f9d4..9a0b67fc 100644 --- a/Mailman/CSRFcheck.py +++ b/Mailman/CSRFcheck.py @@ -55,7 +55,7 @@ def csrf_token(mlist, contexts, user=None): token = binascii.hexlify(marshal.dumps((issued, keymac))) return token -def csrf_check(mlist, token, options_user=None): +def csrf_check(mlist, token, cgi_user=None): """ check token by mailman cookie validation algorithm """ try: issued, keymac = marshal.loads(binascii.unhexlify(token)) @@ -67,12 +67,25 @@ def csrf_check(mlist, token, options_user=None): key, user = key.split('+', 1) else: user = None + # Don't allow unprivileged tokens for admin or admindb. + if cgi_user == 'admin': + if key not in ('admin', 'site'): + syslog('mischief', + 'admin form submitted with CSRF token issued for %s.', + key + '+' + user if user else key) + return False + elif cgi_user == 'admindb': + if key not in ('moderator', 'admin', 'site'): + syslog('mischief', + 'admindb form submitted with CSRF token issued for %s.', + key + '+' + user if user else key) + return False 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: + if cgi_user and cgi_user != raw_user: syslog('mischief', 'Form for user %s submitted with CSRF token ' 'issued for %s.', diff --git a/Mailman/Cgi/admin.py b/Mailman/Cgi/admin.py index b5f14824..a25d7e74 100644 --- a/Mailman/Cgi/admin.py +++ b/Mailman/Cgi/admin.py @@ -107,7 +107,8 @@ def main(): 'legend'] params = cgidata.keys() if set(params) - set(safe_params): - csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token')) + csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token'), + 'admin') else: csrf_checked = True # if password is present, void cookie to force password authentication. diff --git a/Mailman/Cgi/admindb.py b/Mailman/Cgi/admindb.py index 45ba6492..a210efd9 100644 --- a/Mailman/Cgi/admindb.py +++ b/Mailman/Cgi/admindb.py @@ -144,7 +144,8 @@ def main(): safe_params = ['adminpw', 'admlogin', 'msgid', 'sender', 'details'] params = cgidata.keys() if set(params) - set(safe_params): - csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token')) + csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token'), + 'admindb') else: csrf_checked = True # if password is present, void cookie to force password authentication. diff --git a/Mailman/Cgi/edithtml.py b/Mailman/Cgi/edithtml.py index 1dd9e87b..170e8116 100644 --- a/Mailman/Cgi/edithtml.py +++ b/Mailman/Cgi/edithtml.py @@ -111,7 +111,8 @@ def main(): safe_params = ['VARHELP', 'adminpw', 'admlogin'] params = cgidata.keys() if set(params) - set(safe_params): - csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token')) + csrf_checked = csrf_check(mlist, cgidata.getfirst('csrf_token'), + 'admin') else: csrf_checked = True # if password is present, void cookie to force password authentication. diff --git a/NEWS b/NEWS index 8b874ee2..6e29cf46 100644 --- a/NEWS +++ b/NEWS @@ -5,7 +5,12 @@ Copyright (C) 1998-2020 by the Free Software Foundation, Inc. Here is a history of user visible changes to Mailman. -2.1.38 (xx-xxx-xxxx) +2.1.38 (30-Nov-2021) + + Security + + - A potential CSRF attack against a list admin from a list member or + moderator has been blocked. CVE-2021-44227 (LP: #1952384) Bug Fixes and other patches -- cgit v1.2.3