CVE-2023-24538
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.28% probability · 82th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-94
- Affected
- golang/go
- Source
- security@golang.org
References
- https://go.dev/cl/482079Patch
- https://go.dev/issue/59234Issue Tracking, Patch
- https://groups.google.com/g/golang-announce/c/Xdv6JL9ENs8Mailing List
- https://pkg.go.dev/vuln/GO-2023-1703Vendor Advisory
- https://security.gentoo.org/glsa/202311-09
- https://go.dev/cl/482079Patch
- https://go.dev/issue/59234Issue Tracking, Patch
- https://groups.google.com/g/golang-announce/c/Xdv6JL9ENs8Mailing List
- https://pkg.go.dev/vuln/GO-2023-1703Vendor Advisory
- https://security.gentoo.org/glsa/202311-09
- https://security.netapp.com/advisory/ntap-20241115-0007/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.