| id: GO-2023-1703 |
| modules: |
| - module: std |
| versions: |
| - fixed: 1.19.8 |
| - introduced: 1.20.0-0 |
| fixed: 1.20.3 |
| vulnerable_at: 1.20.2 |
| packages: |
| - package: html/template |
| symbols: |
| - tJS |
| - tJSDelimited |
| derived_symbols: |
| - Template.Execute |
| - Template.ExecuteTemplate |
| summary: Backticks not treated as string delimiters in html/template |
| description: |- |
| Templates do not properly consider backticks (`) as Javascript string |
| delimiters, and do not escape them as expected. |
| |
| Backticks are used, since ES6, for JS template literals. If a template contains |
| a Go template action within a Javascript template literal, the contents of the |
| action can be used to terminate the literal, injecting arbitrary Javascript code |
| into the Go template. |
| |
| As ES6 template literals are rather complex, and themselves can do string |
| interpolation, the decision was made to simply disallow Go template actions from |
| being used inside of them (e.g. "var a = {{.}}"), since there is no obviously |
| safe way to allow this behavior. This takes the same approach as |
| github.com/google/safehtml. |
| |
| With fix, Template.Parse returns an Error when it encounters templates like |
| this, with an ErrorCode of value 12. This ErrorCode is currently unexported, but |
| will be exported in the release of Go 1.21. |
| |
| Users who rely on the previous behavior can re-enable it using the GODEBUG flag |
| jstmpllitinterp=1, with the caveat that backticks will now be escaped. This |
| should be used with caution. |
| credits: |
| - Sohom Datta, Manipal Institute of Technology |
| references: |
| - report: https://go.dev/issue/59234 |
| - fix: https://go.dev/cl/482079 |
| - web: https://groups.google.com/g/golang-announce/c/Xdv6JL9ENs8 |
| cve_metadata: |
| id: CVE-2023-24538 |
| cwe: 'CWE-94: Improper Control of Generation of Code (''Code Injection'')' |
