From 22c1d18a276a6edadfb140ad7013ed74b7ed792b Mon Sep 17 00:00:00 2001 From: Michael Anthony Knyszek Date: Tue, 4 Apr 2023 22:07:09 +0000 Subject: [release-branch.go1.19] html/template,mime/multipart: document new GODEBUG settings This change documents the new GODEBUG settings introduced for html/template and mime/multipart, released with Go 1.19.8 and Go 1.20.3 as part of a security fix. Updates #59153. For #59269. Updates #59234. For #59271. Change-Id: I25f4d8245da3301dccccfb44da8ff1a5985392a4 Reviewed-on: https://go-review.googlesource.com/c/go/+/482535 TryBot-Result: Gopher Robot Auto-Submit: Michael Knyszek Reviewed-by: Damien Neil Run-TryBot: Michael Knyszek --- src/html/template/doc.go | 7 +++++++ src/mime/multipart/multipart.go | 15 +++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/src/html/template/doc.go b/src/html/template/doc.go index 5d1631b266..ce7b094d9a 100644 --- a/src/html/template/doc.go +++ b/src/html/template/doc.go @@ -231,5 +231,12 @@ Least Surprise Property: "A developer (or code reviewer) familiar with HTML, CSS, and JavaScript, who knows that contextual autoescaping happens should be able to look at a {{.}} and correctly infer what sanitization happens." + +As a consequence of the Least Surprise Property, template actions within an +ECMAScript 6 template literal are disabled by default. +Handling string interpolation within these literals is rather complex resulting +in no clear safe way to support it. +To re-enable template actions within ECMAScript 6 template literals, use the +GODEBUG=jstmpllitinterp=1 environment variable. */ package template diff --git a/src/mime/multipart/multipart.go b/src/mime/multipart/multipart.go index fab676a70a..de533120cd 100644 --- a/src/mime/multipart/multipart.go +++ b/src/mime/multipart/multipart.go @@ -9,6 +9,21 @@ Package multipart implements MIME multipart parsing, as defined in RFC The implementation is sufficient for HTTP (RFC 2388) and the multipart bodies generated by popular browsers. + +# Limits + +To protect against malicious inputs, this package sets limits on the size +of the MIME data it processes. + +Reader.NextPart and Reader.NextRawPart limit the number of headers in a +part to 10000 and Reader.ReadForm limits the total number of headers in all +FileHeaders to 10000. +These limits may be adjusted with the GODEBUG=multipartmaxheaders= +setting. + +Reader.ReadForm further limits the number of parts in a form to 1000. +This limit may be adjusted with the GODEBUG=multipartmaxparts= +setting. */ package multipart -- cgit v1.2.3-54-g00ecf