Active Record RCE bug with Serialized Columns

When serialized columns that use YAML (the default) are deserialized, Rails uses YAML.unsafe_load to convert the YAML data in to Ruby objects. If an attacker can manipulate data in the database (via means like SQL injection), then it may be possible for the attacker to escalate to an RCE.

There are no feasible workarounds for this issue, but other coders (such as JSON) are not impacted.

Denial of Service Vulnerability in ActiveRecord's PostgreSQL adapter

There is a potential denial of service vulnerability present in ActiveRecord’s PostgreSQL adapter.

This has been assigned the CVE identifier CVE-2022-44566.

Versions Affected: All. Not affected: None. Fixed Versions: 5.2.8.15 (Rails LTS, which is a paid service and not part of the rubygem), 6.1.7.1, 7.0.4.1

Impact: In ActiveRecord <7.0.4.1 and <6.1.7.1, when a value outside the range for a 64bit signed integer is provided to the PostgreSQL connection adapter, it will treat the target column type as numeric. Comparing integer values against numeric values can result in a slow sequential scan resulting in potential Denial of Service. Releases

The fixed releases are available at the normal locations. Workarounds

Ensure that user supplied input which is provided to ActiveRecord clauses do not contain integers wider than a signed 64bit representation or floats. Patches

To aid users who aren’t able to upgrade immediately we have provided patches for the supported release series in accordance with our maintenance policy 1 regarding security issues. They are in git-am format and consist of a single changeset.

6-1-Added-integer-width-check-to-PostgreSQL-Quoting.patch - Patch for 6.1 series
7-0-Added-integer-width-check-to-PostgreSQL-Quoting.patch - Patch for 7.0 series

Active Record subject to Regular Expression Denial-of-Service (ReDoS)

The PostgreSQL adapter in Active Record before 6.1.2.1, 6.0.3.5, 5.2.4.5 suffers from a regular expression denial of service (REDoS) vulnerability. Carefully crafted input can cause the input validation in the money type of the PostgreSQL adapter in Active Record to spend too much time in a regular expression, resulting in the potential for a DoS attack. This only impacts Rails applications that are using PostgreSQL along with money type columns that take user input.

Possible DoS Vulnerability in Active Record PostgreSQL adapter

There is a possible DoS vulnerability in the PostgreSQL adapter in Active Record. This vulnerability has been assigned the CVE identifier CVE-2021-22880.

Versions Affected: >= 4.2.0 Not affected: < 4.2.0 Fixed Versions: 6.1.2.1, 6.0.3.5, 5.2.4.5

Impact

Carefully crafted input can cause the input validation in the money type of the PostgreSQL adapter in Active Record to spend too much time in a regular expression, resulting in the potential for a DoS attack.

This only impacts Rails applications that are using PostgreSQL along with money type columns that take user input.

Workarounds

In the case a patch can't be applied, the following monkey patch can be used in an initializer:

module ActiveRecord
  module ConnectionAdapters
    module PostgreSQL
      module OID # :nodoc:
        class Money < Type::Decimal # :nodoc:
          def cast_value(value)
            return value unless ::String === value

            value = value.sub(/^\((.+)\)$/, '-\1') # (4)
            case value
            when /^-?\D*+[\d,]+\.\d{2}$/  # (1)
              value.gsub!(/[^-\d.]/, "")
            when /^-?\D*+[\d.]+,\d{2}$/  # (2)
              value.gsub!(/[^-\d,]/, "").sub!(/,/, ".")
            end

            super(value)
          end
        end
      end
    end
  end
end

Possible RCE escalation bug with Serialized Columns in Active Record

There is a possible escalation to RCE when using YAML serialized columns in Active Record. This vulnerability has been assigned the CVE identifier CVE-2022-32224.

Versions Affected: All. Not affected: None Fixed Versions: 7.0.3.1, 6.1.6.1, 6.0.5.1, 5.2.8.1

Impact

When serialized columns that use YAML (the default) are deserialized, Rails uses YAML.unsafe_load to convert the YAML data in to Ruby objects. If an attacker can manipulate data in the database (via means like SQL injection), then it may be possible for the attacker to escalate to an RCE.

Impacted Active Record models will look something like this:

class User < ApplicationRecord
  serialize :options       # Vulnerable: Uses YAML for serialization
  serialize :values, Array # Vulnerable: Uses YAML for serialization
  serialize :values, JSON  # Not vulnerable
end

All users running an affected release should either upgrade or use one of the workarounds immediately.

Releases

The FIXED releases are available at the normal locations.

The released versions change the default YAML deserializer to use YAML.safe_load, which prevents deserialization of possibly dangerous objects. This may introduce backwards compatibility issues with existing data.

In order to cope with that situation, the released version also contains two new Active Record configuration options. The configuration options are as follows:

• config.active_record.use_yaml_unsafe_load

When set to true, this configuration option tells Rails to use the old unsafe YAML loading strategy, maintaining the existing behavior but leaving the possible escalation vulnerability in place. Setting this option to true is not recommended, but can aid in upgrading.

• config.active_record.yaml_column_permitted_classes

The safe YAML loading method does not allow all classes to be deserialized by default. This option allows you to specify classes deemed safe in your application. For example, if your application uses Symbol and Time in serialized data, you can add Symbol and Time to the allowed list as follows:

config.active_record.yaml_column_permitted_classes = [Symbol, Date, Time]

Workarounds

There are no feasible workarounds for this issue, but other coders (such as JSON) are not impacted.

Denial of Service Vulnerability in ActiveRecord’s PostgreSQL adapter

There is a potential denial of service vulnerability present in ActiveRecord’s PostgreSQL adapter.

This has been assigned the CVE identifier CVE-2022-44566.

Versions Affected: All. Not affected: None. Fixed Versions: 5.2.8.15 (Rails LTS), 6.1.7.1, 7.0.4.1

Impact

In ActiveRecord <7.0.4.1 and <6.1.7.1, when a value outside the range for a 64bit signed integer is provided to the PostgreSQL connection adapter, it will treat the target column type as numeric. Comparing integer values against numeric values can result in a slow sequential scan resulting in potential Denial of Service.

Workarounds

Ensure that user supplied input which is provided to ActiveRecord clauses do not contain integers wider than a signed 64bit representation or floats.