We have just released Go 1.13.1 and Go 1.12.10 to address a recently reported security issue. We recommend that all affected users update to one of these releases (if you’re not sure which, choose Go 1.13.1).
net/http (through net/textproto) used to accept and normalize invalid HTTP/1.1 headers with a space before the colon, in violation of RFC 7230. If a Go server is used behind an uncommon reverse proxy that accepts and forwards but doesn't normalize such invalid headers, the reverse proxy and the server can interpret the headers differently. This can lead to filter bypasses or request smuggling
, the latter if requests from separate clients are multiplexed onto the same upstream connection by the proxy. Such invalid headers are now rejected by Go servers, and passed without normalization to Go client applications.
The issue is CVE-2019-16276 and Go issue golang.org/issue/34540
Thanks to Andrew Stucki, Adam Scarr (99designs.com
), and Jan Masarik (masarik.sh) for discovering and reporting this issue.
Downloads are available at https://golang.org/dl
for all supported platforms.
Filippo on behalf of the Go team