Bug 892866 (CVE-2013-0155)

Summary: CVE-2013-0155 rubygem-actionpack, rubygem-activerecord: Unsafe Query Generation Risk in Ruby on Rails
Product: [Other] Security Response Reporter: Kurt Seifried <kseifried>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: bkabrda, bkearney, bleanhar, cpelland, daviddavis, jialiu, jlieskov, jrusnack, katello-bugs, katello-internal, lmeyer, mmaslano, mmccune, morazi, msuchy, rmillner, security-response-team, tdawson, tkramer, vondruch
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,public=20130108,reported=20130107,source=upstream,cvss2=6.4/AV:N/AC:L/Au:N/C:P/I:P/A:N,epel-5/rubygem-actionpack=notaffected,fedora-all/rubygem-actionpack=affected,openshift-1/ruby193-rubygem-actionpack=affected,openshift-1/rubygem-actionpack=affected,sam-1/rubygem-actionpack=affected,cloudformscommon-1/rubygem-actionpack=affected,openshift-enterprise-1/ruby193-rubygem-actionpack=affected,openshift-enterprise-1/rubygem-actionpack=affected,cwe=CWE-89
Fixed In Version: rubygem-activerecord 3.2.11, rubygem-activerecord 3.1.10, rubygem-activerecord 3.0.19, rubygem-actionpack 3.2.11, rubygem-actionpack 3.1.10, rubygem-actionpack 3.0.19 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-04-10 18:29:35 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Bug Depends On: 892873, 892875, 892877, 893281, 916342    
Bug Blocks: 893691    
Attachments:
Description Flags
actionpack-CVE-2012-0155-3-0-null_array_param.patch
none
actionpack-CVE-2012-0155-3-1-null_array_param.patch
none
actionpack-CVE-2012-0155-3-2-null_array_param.patch
none
actionpack-CVE-2012-0155-3-2-unsafe_query.patch
none
actionpack-CVE-2013-0155-3-0-null_array_param.patch
none
actionpack-CVE-2013-0155-3-1-null_array_param.patch
none
actionpack-CVE-2013-0155-3-2-null_array_param.patch none

Description Kurt Seifried 2013-01-08 00:24:45 EST
Damien Mathieu (42@dmathieu.com) reports:

Unsafe Query Generation Risk in Ruby on Rails

There is a vulnerability when Active Record is used in conjunction with JSON 
parameter parsing. This vulnerability has been assigned the CVE identifier 
CVE-2013-0155.

Versions Affected:  3.x series
Not affected:       2.x series
Fixed Versions:     3.2.11, 3.1.10, 3.0.19

Impact
------

Due to the way Active Record interprets parameters in combination with the way
that JSON parameters are parsed, it is possible for an attacker to issue 
unexpected database queries with "IS NULL" or empty where clauses.  This issue 
does *not* let an attacker insert arbitrary values into an SQL query, however 
they can cause the query to check for NULL or eliminate a WHERE clause when 
most users wouldn't expect it.

For example, a system has password reset with token functionality:

    unless params[:token].nil?
      user = User.find_by_token(params[:token])
      user.reset_password!
    end

An attacker can craft a request such that `params[:token]` will return `[nil]`.
The `[nil]` value will bypass the test for nil, but will still add an 
"IN ('xyz', NULL)" clause to the SQL query.

Similarly, an attacker can craft a request such that `params[:token]` will 
return an empty hash.  An empty hash will eliminate the WHERE clause of the 
query, but can bypass the `nil?` check.

Note that this impacts not only dynamic finders (`find_by_*`) but also 
relations (`User.where(:name => params[:name])`).

All users running an affected release should either upgrade or use one of the 
work arounds immediately. All users running an affected release should upgrade
immediately. Please note, this vulnerability is a variant of CVE-2012-2660, 
and CVE-2012-2694.  Even if you upgraded to address those issues, you must 
take action again.

If this chance in behavior impacts your application, you can manually decode 
the original values from the request like so:

    ActiveSupport::JSON.decode(request.body)

Releases
--------
The FIXED releases are available at the normal locations.

Workarounds
-----------
This problem can be mitigated by casting the parameter to a string before 
passing it to Active Record.  For example:

    unless params[:token].nil? || params[:token].to_s.empty?
      user = User.find_by_token(params[:token].to_s)
      user.reset_password!
    end
An attacker can craft a request such that `params[:token]` will return `[nil]`.
The `[nil]` value will bypass the test for nil, but will still add an 
"IN ('xyz', NULL)" clause to the SQL query.

Similarly, an attacker can craft a request such that `params[:token]` will 
return an empty hash.  An empty hash will eliminate the WHERE clause of the 
query, but can bypass the `nil?` check.

Note that this impacts not only dynamic finders (`find_by_*`) but also 
relations (`User.where(:name => params[:name])`).

All users running an affected release should either upgrade or use one of the 
work arounds immediately. All users running an affected release should upgrade
immediately. Please note, this vulnerability is a variant of CVE-2012-2660, 
and CVE-2012-2694.  Even if you upgraded to address those issues, you must 
take action again.

If this chance in behavior impacts your application, you can manually decode 
the original values from the request like so:

    ActiveSupport::JSON.decode(request.body)

Releases
--------
The FIXED releases are available at the normal locations.

Workarounds
-----------
This problem can be mitigated by casting the parameter to a string before 
passing it to Active Record.  For example:

    unless params[:token].nil? || params[:token].to_s.empty?
      user = User.find_by_token(params[:token].to_s)
      user.reset_password!
    end

Note the parameter is still cast to a string before being sent to Active 
Record. This is because an array with a nil value can still bypass the 
`to_s.empty?` test:

    >> ['xyz', nil].to_s
    => "xyz"
    >> ['xyz', nil].to_s.empty?
    => false
Comment 1 Kurt Seifried 2013-01-08 01:01:39 EST
Created attachment 674505 [details]
actionpack-CVE-2012-0155-3-0-null_array_param.patch
Comment 2 Kurt Seifried 2013-01-08 01:02:02 EST
Created attachment 674506 [details]
actionpack-CVE-2012-0155-3-1-null_array_param.patch
Comment 3 Kurt Seifried 2013-01-08 01:02:28 EST
Created attachment 674507 [details]
actionpack-CVE-2012-0155-3-2-null_array_param.patch
Comment 4 Kurt Seifried 2013-01-08 01:02:46 EST
Created attachment 674508 [details]
actionpack-CVE-2012-0155-3-2-unsafe_query.patch
Comment 9 Kurt Seifried 2013-01-08 16:24:03 EST
Created attachment 675073 [details]
actionpack-CVE-2013-0155-3-2-unsafe_query.patch
Comment 10 Kurt Seifried 2013-01-08 16:24:42 EST
Created attachment 675074 [details]
actionpack-CVE-2013-0155-3-0-null_array_param.patch
Comment 11 Kurt Seifried 2013-01-08 16:25:30 EST
Created attachment 675075 [details]
actionpack-CVE-2013-0155-3-1-null_array_param.patch
Comment 12 Kurt Seifried 2013-01-08 16:25:51 EST
Created attachment 675076 [details]
actionpack-CVE-2013-0155-3-2-null_array_param.patch
Comment 13 Vincent Danen 2013-01-08 21:20:59 EST
Created rubygem-actionpack tracking bugs for this issue

Affects: fedora-all [bug 893281]
Comment 14 Kurt Seifried 2013-01-09 01:37:26 EST
The upstream report:

https://groups.google.com/forum/#!topic/rubyonrails-security/t1WFuuQyavI
Comment 15 Tomas Hoger 2013-01-09 07:46:55 EST
The fix for this issue was reported to introduce a regression:

https://github.com/rails/rails/issues/8832
Comment 17 errata-xmlrpc 2013-01-10 15:42:47 EST
This issue has been addressed in following products:

  Red Hat Subscription Asset Manager 1.1

Via RHSA-2013:0154 https://rhn.redhat.com/errata/RHSA-2013-0154.html
Comment 18 errata-xmlrpc 2013-01-10 17:41:38 EST
This issue has been addressed in following products:

  CloudForms for RHEL 6

Via RHSA-2013:0155 https://rhn.redhat.com/errata/RHSA-2013-0155.html
Comment 19 Fedora Update System 2013-01-19 22:40:20 EST
rubygem-actionpack-3.2.8-2.fc18, rubygem-activerecord-3.2.8-3.fc18, rubygem-activesupport-3.2.8-2.fc18 has been pushed to the Fedora 18 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 20 Fedora Update System 2013-01-22 20:33:23 EST
rubygem-actionpack-3.0.10-10.fc16, rubygem-activerecord-3.0.10-5.fc16, rubygem-activesupport-3.0.10-5.fc16, rubygem-activemodel-3.0.10-2.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 21 Fedora Update System 2013-01-22 20:53:10 EST
rubygem-actionpack-3.0.11-8.fc17, rubygem-activerecord-3.0.11-5.fc17, rubygem-activemodel-3.0.11-2.fc17, rubygem-activesupport-3.0.11-7.fc17 has been pushed to the Fedora 17 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 23 errata-xmlrpc 2013-02-28 14:08:48 EST
This issue has been addressed in following products:

  RHEL 6 Version of OpenShift Enterprise

Via RHSA-2013:0582 https://rhn.redhat.com/errata/RHSA-2013-0582.html