ghsa-cfjv-5498-mph5
Vulnerability from github
There is a potential Cross-Site Scripting (XSS) vulnerability in Action View's translation helpers. Views that allow the user to control the default (not found) value of the t and translate helpers could be susceptible to XSS attacks.
Impact
When an HTML-unsafe string is passed as the default for a missing translation key named html or ending in _html, the default string is incorrectly marked as HTML-safe and not escaped. Vulnerable code may look like the following examples:
```erb <%# The welcome_html translation is not defined for the current locale: %> <%= t("welcome_html", default: untrusted_user_controlled_string) %>
<%# Neither the title.html translation nor the missing.html translation is defined for the current locale: %> <%= t("title.html", default: [:"missing.html", untrusted_user_controlled_string]) %> ```
Patches
Patched Rails versions, 6.0.3.3 and 5.2.4.4, are available from the normal locations.
The patches have also been applied to the master, 6-0-stable, and 5-2-stable branches on GitHub. If you track any of these branches, you should update to the latest.
To aid users who aren’t able to upgrade immediately, we’ve provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
- 5-2-translate-helper-xss.patch — patch for the 5.2 release series
- 6-0-translate-helper-xss.patch — patch for the 6.0 release series
Please note that only the 5.2 and 6.0 release series are currently supported. Users of earlier, unsupported releases are advised to update as soon as possible, as we cannot provide security fixes for unsupported releases.
Workarounds
Impacted users who can’t upgrade to a patched Rails version can avoid this issue by manually escaping default translations with the html_escape helper (aliased as h):
erb
<%= t("welcome_html", default: h(untrusted_user_controlled_string)) %>
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.2.4.3"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "5.2.4.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 6.0.3.2"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "6.0.0.0"
},
{
"fixed": "6.0.3.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-15169"
],
"database_specific": {
"cwe_ids": [
"CWE-79"
],
"github_reviewed": true,
"github_reviewed_at": "2020-09-11T15:19:29Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "There is a potential Cross-Site Scripting (XSS) vulnerability in Action View\u0027s translation helpers. Views that allow the user to control the default (not found) value of the `t` and `translate` helpers could be susceptible to XSS attacks.\n\n### Impact\n\nWhen an HTML-unsafe string is passed as the default for a missing translation key [named `html` or ending in `_html`](https://guides.rubyonrails.org/i18n.html#using-safe-html-translations), the default string is incorrectly marked as HTML-safe and not escaped. Vulnerable code may look like the following examples:\n\n```erb\n\u003c%# The welcome_html translation is not defined for the current locale: %\u003e\n\u003c%= t(\"welcome_html\", default: untrusted_user_controlled_string) %\u003e\n\n\u003c%# Neither the title.html translation nor the missing.html translation is defined for the current locale: %\u003e\n\u003c%= t(\"title.html\", default: [:\"missing.html\", untrusted_user_controlled_string]) %\u003e\n```\n\n### Patches\n\nPatched Rails versions, 6.0.3.3 and 5.2.4.4, are available from the normal locations.\n\nThe patches have also been applied to the `master`, `6-0-stable`, and `5-2-stable` branches on GitHub. If you track any of these branches, you should update to the latest.\n\nTo aid users who aren\u2019t able to upgrade immediately, we\u2019ve provided patches for the two supported release series. They are in git-am format and consist of a single changeset.\n\n* [5-2-translate-helper-xss.patch](https://gist.github.com/georgeclaghorn/a466e103922ee81f24c32c9034089442#file-5-2-translate-helper-xss-patch) \u2014 patch for the 5.2 release series\n* [6-0-translate-helper-xss.patch](https://gist.github.com/georgeclaghorn/a466e103922ee81f24c32c9034089442#file-6-0-translate-helper-xss-patch) \u2014 patch for the 6.0 release series\n\nPlease note that only the 5.2 and 6.0 release series are currently supported. Users of earlier, unsupported releases are advised to update as soon as possible, as we cannot provide security fixes for unsupported releases.\n\n### Workarounds\n\nImpacted users who can\u2019t upgrade to a patched Rails version can avoid this issue by manually escaping default translations with the `html_escape` helper (aliased as `h`):\n\n```erb\n\u003c%= t(\"welcome_html\", default: h(untrusted_user_controlled_string)) %\u003e\n```",
"id": "GHSA-cfjv-5498-mph5",
"modified": "2023-05-04T19:48:00Z",
"published": "2020-09-11T15:19:57Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/rails/rails/security/advisories/GHSA-cfjv-5498-mph5"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-15169"
},
{
"type": "WEB",
"url": "https://github.com/rails/rails/commit/e663f084460ea56c55c3dc76f78c7caeddeeb02e"
},
{
"type": "PACKAGE",
"url": "https://github.com/rails/rails"
},
{
"type": "WEB",
"url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionview/CVE-2020-15169.yml"
},
{
"type": "WEB",
"url": "https://groups.google.com/g/rubyonrails-security/c/b-C9kSGXYrc"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2020/10/msg00015.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XJ7NUWXAEVRQCROIIBV4C6WXO6IR3KSB"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2020/dsa-4766"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "XSS in Action View"
}