Advisory details:
github_osv / GHSA-65cv-r6x7-79hv
| Advisory ID | github_osv/GHSA-65cv-r6x7-79hv |
| Aliases |
CVE-2020-5267
|
| Summary | Cross site scripting vulnerability in ActionView There is a possible cross site scripting (XSS) vulnerability in ActionView's JavaScript literal escape helpers. Views that use the `j` or `escape_javascript` methods may be susceptible to XSS attacks. ### Impact There is a possible XSS vulnerability in the `j` and `escape_javascript` methods in ActionView. These methods are used for escaping JavaScript string literals. Impacted code will look something like this: ```erb <script>let a = `<%= j unknown_input %>`</script> ``` or ```erb <script>let a = `<%= escape_javascript unknown_input %>`</script> ``` ### Releases The 6.0.2.2 and 5.2.4.2 releases are available at the normal locations. ### Workarounds For those that can't upgrade, the following monkey patch may be used: ```ruby ActionView::Helpers::JavaScriptHelper::JS_ESCAPE_MAP.merge!( { "`" => "\\`", "$" => "\\$" } ) module ActionView::Helpers::JavaScriptHelper alias :old_ej :escape_javascript alias :old_j :j def escape_javascript(javascript) javascript = javascript.to_s if javascript.empty? result = "" else result = javascript.gsub(/(\\|<\/|\r\n|\342\200\250|\342\200\251|[\n\r"']|[`]|[$])/u, JS_ESCAPE_MAP) end javascript.html_safe? ? result.html_safe : result end alias :j :escape_javascript end ``` ### Patches To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset. * [5-2-js-helper-xss.patch](https://gist.github.com/tenderlove/c042ff49f0347c37e99183a6502accc6#file-5-2-js-helper-xss-patch) - Patch for 5.2 series * [6-0-js-helper-xss.patch](https://gist.github.com/tenderlove/c042ff49f0347c37e99183a6502accc6#file-6-0-js-helper-xss-patch) - Patch for 6.0 series Please note that only the 5.2 and 6.0 series are supported at present. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases. ### Credits Thanks to Jesse Campos from Chef Secure |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 4.3 |
| Risk | 2.1 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| There are no known CWE. |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | 4.8 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/03/GHSA-65cv-r6x7-79hv/GHSA-65cv-r6x7-79hv.json |
| generic_textual | MODERATE |
No exploits are available.
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
There are no SSVC decisions available.