Affected: tzinfo

TZInfo is a Ruby library that provides access to time zone data and allows times to be converted using time zone rules. Versions prior to 0.36.1, as well as those prior to 1.2.10 when used with the Ruby data source tzinfo-data, are vulnerable to relative path traversal. With the Ruby data source, time zones are defined in Ruby files. There is one file per time zone. Time zone files are loaded with `require` on demand. In the affected versions, `TZInfo::Timezone.get` fails to validate time zone identifiers correctly, allowing a new line character within the identifier. With Ruby version 1.9.3 and later, `TZInfo::Timezone.get` can be made to load unintended files with `require`, executing them within the Ruby process. Versions 0.3.61 and 1.2.10 include fixes to correctly validate time zone identifiers. Versions 2.0.0 and later are not vulnerable. Version 0.3.61 can still load arbitrary files from the Ruby load path if their name follows the rules for a valid time zone identifier and the file has a prefix of `tzinfo/definition` within a directory in the load path. Applications should ensure that untrusted files are not placed in a directory on the load path. As a workaround, the time zone identifier can be validated before passing to `TZInfo::Timezone.get` by ensuring it matches the regular expression `\A[A-Za-z0-9+\-_]+(?:\/[A-Za-z0-9+\-_]+)*\z`.

Affected: RubyGems: tzinfo

### Impact

#### Affected versions

- 0.3.60 and earlier. - 1.0.0 to 1.2.9 when used with the Ruby data source (tzinfo-data).

#### Vulnerability

With the Ruby data source (the tzinfo-data gem for tzinfo version 1.0.0 and later and built-in to earlier versions), time zones are defined in Ruby files. There is one file per time zone. Time zone files are loaded with `require` on demand. In the affected versions, `TZInfo::Timezone.get` fails to validate time zone identifiers correctly, allowing a new line character within the identifier. With Ruby version 1.9.3 and later, `TZInfo::Timezone.get` can be made to load unintended files with `require`, executing them within the Ruby process.

For example, with version 1.2.9, you can run the following to load a file with path `/tmp/payload.rb`:

```ruby TZInfo::Timezone.get("foo\n/../../../../../../../../../../../../../../../../tmp/payload") ```

The exact number of parent directory traversals needed will vary depending on the location of the tzinfo-data gem.

TZInfo versions 1.2.6 to 1.2.9 can be made to load files from outside of the Ruby load path. Versions up to and including 1.2.5 can only be made to load files from directories within the load path.

This could be exploited in, for example, a Ruby on Rails application using tzinfo version 1.2.9, that allows file uploads and has a time zone selector that accepts arbitrary time zone identifiers. The CVSS score and severity have been set on this basis.

Versions 2.0.0 and late…