ghsa-5cm2-9h8c-rvfx
Vulnerability from github
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 later are not vulnerable.
Patches
Versions 0.3.61 and 1.2.10 include fixes to correctly validate time zone identifiers (commit 9eddbb5c0e682736f61d0dd803b6031a5db9eadf for 0.3.x and commit 9905ca93abf7bf3e387bd592406e403cd18334c7 for 1.2.x).
Note that 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. For example if /tmp/upload was in the load path, then TZInfo::Timezone.get('foo') could load a file with path /tmp/upload/tzinfo/definition/foo.rb. Applications should ensure that untrusted files are not placed in a directory on the load path.
Workarounds
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.
For more information
If you have any questions or comments about this advisory: - Open an issue in the tzinfo repository.
{
"affected": [
{
"package": {
"ecosystem": "RubyGems",
"name": "tzinfo"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.3.61"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "RubyGems",
"name": "tzinfo"
},
"ranges": [
{
"events": [
{
"introduced": "1.0.0"
},
{
"fixed": "1.2.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-31163"
],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-23"
],
"github_reviewed": true,
"github_reviewed_at": "2022-07-21T21:39:29Z",
"nvd_published_at": "2022-07-22T04:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\n\n#### Affected versions\n\n - 0.3.60 and earlier.\n - 1.0.0 to 1.2.9 when used with the Ruby data source (tzinfo-data).\n\n#### Vulnerability \n\nWith 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.\n\nFor example, with version 1.2.9, you can run the following to load a file with path `/tmp/payload.rb`:\n\n```ruby\nTZInfo::Timezone.get(\"foo\\n/../../../../../../../../../../../../../../../../tmp/payload\")\n```\n\nThe exact number of parent directory traversals needed will vary depending on the location of the tzinfo-data gem.\n\nTZInfo 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. \n\nThis 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.\n\nVersions 2.0.0 and later are not vulnerable.\n\n### Patches\n\nVersions 0.3.61 and 1.2.10 include fixes to correctly validate time zone identifiers (commit 9eddbb5c0e682736f61d0dd803b6031a5db9eadf for 0.3.x and commit 9905ca93abf7bf3e387bd592406e403cd18334c7 for 1.2.x).\n\nNote that 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. For example if `/tmp/upload` was in the load path, then `TZInfo::Timezone.get(\u0027foo\u0027)` could load a file with path `/tmp/upload/tzinfo/definition/foo.rb`. Applications should ensure that untrusted files are not placed in a directory on the load path.\n\n### Workarounds\n\nAs 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`.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n - Open an issue in [the tzinfo repository](https://github.com/tzinfo/tzinfo).",
"id": "GHSA-5cm2-9h8c-rvfx",
"modified": "2022-08-10T23:48:58Z",
"published": "2022-07-21T21:39:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/tzinfo/tzinfo/security/advisories/GHSA-5cm2-9h8c-rvfx"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-31163"
},
{
"type": "WEB",
"url": "https://github.com/tzinfo/tzinfo/commit/9905ca93abf7bf3e387bd592406e403cd18334c7"
},
{
"type": "WEB",
"url": "https://github.com/tzinfo/tzinfo/commit/9eddbb5c0e682736f61d0dd803b6031a5db9eadf"
},
{
"type": "WEB",
"url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/tzinfo/CVE-2022-31163.yml"
},
{
"type": "PACKAGE",
"url": "https://github.com/tzinfo/tzinfo"
},
{
"type": "WEB",
"url": "https://github.com/tzinfo/tzinfo/releases/tag/v0.3.61"
},
{
"type": "WEB",
"url": "https://github.com/tzinfo/tzinfo/releases/tag/v1.2.10"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/08/msg00009.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "TZInfo relative path traversal vulnerability allows loading of arbitrary files"
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.