go1.20.4 (released 2023-05-02) includes three security fixes to the html/template
package, as well as bug fixes to the compiler, the runtime, and the crypto/subtle,
crypto/tls, net/http, and syscall packages. See the Go 1.20.4 milestone on our
issue tracker for details:
https://github.com/golang/go/issues?q=milestone%3AGo1.20.4+label%3ACherryPickApproved
release notes: https://go.dev/doc/devel/release#go1.20.4
full diff: https://github.com/golang/go/compare/go1.20.3...go1.20.4
from the announcement:
> These minor releases include 3 security fixes following the security policy:
>
> - html/template: improper sanitization of CSS values
>
> Angle brackets (`<>`) were not considered dangerous characters when inserted
> into CSS contexts. Templates containing multiple actions separated by a '/'
> character could result in unexpectedly closing the CSS context and allowing
> for injection of unexpected HMTL, if executed with untrusted input.
>
> Thanks to Juho Nurminen of Mattermost for reporting this issue.
>
> This is CVE-2023-24539 and Go issue https://go.dev/issue/59720.
>
> - html/template: improper handling of JavaScript whitespace
>
> Not all valid JavaScript whitespace characters were considered to be
> whitespace. Templates containing whitespace characters outside of the character
> set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain
> actions may not be properly sanitized during execution.
>
> Thanks to Juho Nurminen of Mattermost for reporting this issue.
>
> This is CVE-2023-24540 and Go issue https://go.dev/issue/59721.
>
> - html/template: improper handling of empty HTML attributes
>
> Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}")
> executed with empty input could result in output that would have unexpected
> results when parsed due to HTML normalization rules. This may allow injection
> of arbitrary attributes into tags.
>
> Thanks to Juho Nurminen of Mattermost for reporting this issue.
>
> This is CVE-2023-29400 and Go issue https://go.dev/issue/59722.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Sebastiaan van Stijn