We have just released Go versions 1.19.4 and 1.18.9, minor point releases.
These minor releases include 2 security fixes following the security policy:
os, net/http: avoid escapes from os.DirFS and http.Dir on Windows
The os.DirFS function and http.Dir type provide access to a tree of files
rooted at a given directory. These functions permitted access to Windows
device files under that root. For example, os.DirFS("C:/tmp").Open("COM1")
would open the COM1 device.
Both os.DirFS and http.Dir only provide read-only filesystem access.
In addition, on Windows, an os.DirFS for the directory
\(the root of the
current drive) can permit a maliciously crafted path to escape from the
drive and access any path on the system.
The behavior of os.DirFS("") has changed. Previously, an empty root was
treated equivalently to "/", so os.DirFS("").Open("tmp") would open the path "/tmp".
This now returns an error.
This is CVE-2022-41720 and Go issue https://go.dev/issue/56694.
net/http: limit canonical header cache by bytes, not entries
An attacker can cause excessive memory growth in a Go server accepting HTTP/2 requests.
HTTP/2 server connections contain a cache of HTTP header keys sent by the client. While the total number of entries in this cache is capped, an attacker sending very large keys can cause the server to allocate approximately 64 MiB per open connection.
This issue is also fixed in golang.org/x/net/http2 vX.Y.Z, for users manually configuring HTTP/2.
Thanks to Josselin Costanzi for reporting this issue.
This is CVE-2022-41717 and Go issue https://go.dev/issue/56350.
View the release notes for more information:
You can download binary and source distributions from the Go website:
To compile from source using a Git clone, update to the release with
git checkout go1.19.4 and build as usual.
Thanks to everyone who contributed to the releases.
Jenny and Michael for the Go team