Ruby on Rails Action View 信息泄漏

2016-03-17T00:00:00
ID SSV:91076
Type seebug
Reporter Root
Modified 2016-03-17T00:00:00

Description

Possible Information Leak Vulnerability in Action View.

There is a possible directory traversal and information leak vulnerability in Action View. This was meant to be fixed on CVE-2016-0752. However the 3.2 patch was not covering all the scenarios. This vulnerability has been assigned the CVE identifier CVE-2016-2097.

Versions Affected: 3.2.x, 4.0.x, 4.1.x Not affected: 4.2+ Fixed Versions: 3.2.22.2, 4.1.14.2

Impact

Applications that pass unverified user input to the render method in a controller may be vulnerable to an information leak vulnerability.

Impacted code will look something like this:

ruby def index render params[:id] end

Carefully crafted requests can cause the above code to render files from unexpected places like outside the application's view directory, and can possibly escalate this to a remote code execution attack.

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.

Workarounds

A workaround to this issue is to not pass arbitrary user input to the render method. Instead, verify that data before passing it to the render method.

For example, change this:

ruby def index render params[:id] end

To this:

```ruby def index render verify_template(params[:id]) end

private def verify_template(name) # add verification logic particular to your application here end ```

Credits

Thanks to both Jyoti Singh and Tobias Kraze from makandra for reporting this and working with us in the patch!