From 00a9b0344097a5dd3ca0b1a59229d3ce70cbd8ae Mon Sep 17 00:00:00 2001 From: Aaron Patterson Date: Wed, 10 Feb 2021 09:36:15 -0800 Subject: [PATCH] Fix possible DoS vector in PostgreSQL money type Carefully crafted input can cause a DoS via the regular expressions used for validating the money format in the PostgreSQL adapter. This patch fixes the regexp. Thanks to @dee-see from Hackerone for this patch! [CVE-2021-22880] --- .../connection_adapters/postgresql/oid/money.rb | 4 ++-- activerecord/test/cases/adapters/postgresql/money_test.rb | 8 ++++++++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb index 357493dfc0..3703e9a646 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb @@ -26,9 +26,9 @@ def cast_value(value) value = value.sub(/^\((.+)\)$/, '-\1') # (4) case value - when /^-?\D*[\d,]+\.\d{2}$/ # (1) + when /^-?\D*+[\d,]+\.\d{2}$/ # (1) value.gsub!(/[^-\d.]/, "") - when /^-?\D*[\d.]+,\d{2}$/ # (2) + when /^-?\D*+[\d.]+,\d{2}$/ # (2) value.gsub!(/[^-\d,]/, "").sub!(/,/, ".") end diff --git a/activerecord/test/cases/adapters/postgresql/money_test.rb b/activerecord/test/cases/adapters/postgresql/money_test.rb index ff2ab22a80..a442ce6d8c 100644 --- a/activerecord/test/cases/adapters/postgresql/money_test.rb +++ b/activerecord/test/cases/adapters/postgresql/money_test.rb @@ -62,6 +62,14 @@ def test_money_type_cast assert_equal(-2.25, type.cast(+"(2.25)")) end + def test_money_regex_backtracking + type = PostgresqlMoney.type_for_attribute("wealth") + Timeout.timeout(0.1) do + assert_equal(0.0, type.cast("$" + "," * 100000 + ".11!")) + assert_equal(0.0, type.cast("$" + "." * 100000 + ",11!")) + end + end + def test_schema_dumping output = dump_table_schema("postgresql_moneys") assert_match %r{t\.money\s+"wealth",\s+scale: 2$}, output -- 2.26.2