tree 9a9727e9dda4d2f97fc37a2dcf9222fb16380418
parent e7c4b07ecf6b367f1afc9cc48cde963829dd0aab
author Roland Shoemaker <bracewell@google.com> 1679335273 -0700
committer Gopher Robot <gobot@golang.org> 1680627558 +0000

[release-branch.go1.20] html/template: disallow actions in JS template literals

ECMAScript 6 introduced template literals[0][1] which are delimited with
backticks. These need to be escaped in a similar fashion to the
delimiters for other string literals. Additionally template literals can
contain special syntax for string interpolation.

There is no clear way to allow safe insertion of actions within JS
template literals, as handling (JS) string interpolation inside of these
literals is rather complex. As such we've chosen to simply disallow
template actions within these template literals.

A new error code is added for this parsing failure case, errJsTmplLit,
but it is unexported as it is not backwards compatible with other minor
release versions to introduce an API change in a minor release. We will
export this code in the next major release.

The previous behavior (with the cavet that backticks are now escaped
properly) can be re-enabled with GODEBUG=jstmpllitinterp=1.

This change subsumes CL471455.

Thanks to Sohom Datta, Manipal Institute of Technology, for reporting
this issue.

Fixes CVE-2023-24538
For #59234
Fixes #59272

[0] https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-template-literals
[1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals

Change-Id: Idff74ec386e9b73d6e9a3c9f71990eabc0ce7506
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1802457
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Julie Qiu <julieqiu@google.com>
Reviewed-by: Roland Shoemaker <bracewell@google.com>
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1802688
Run-TryBot: Roland Shoemaker <bracewell@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/481993
Run-TryBot: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>