Arch Linux alert ASA-202107-42 (go)

From:
             
 
Jonas Witschel via arch-security <arch-security@lists.archlinux.org>
To:
             
 
arch-security@lists.archlinux.org
Subject:
             
 
[ASA-202107-42] go: denial of service
Date:
             
 
Tue, 20 Jul 2021 21:30:53 +0200
Message-ID:
             
 
<20210720193053.uvrjkk2c7g55ztmg@archlinux.org>
Cc:
             
 
Jonas Witschel <diabonas@archlinux.org>
Arch Linux Security Advisory ASA-202107-42
==========================================

Severity: Low
Date    : 2021-07-20
CVE-ID  : CVE-2021-34558
Package : go
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-2147

Summary
=======

The package go before version 2:1.16.6-1 is vulnerable to denial of
service.

Resolution
==========

Upgrade to 2:1.16.6-1.

# pacman -Syu "go>=2:1.16.6-1"

The problem has been fixed upstream in version 1.16.6.

Workaround
==========

Clients that disable all TLS_RSA cipher suites (that is, TLS 1.0–1.2
cipher suites without ECDHE), as well as TLS 1.3-only clients, are
unaffected.

Description
===========

A security issue has been found in Go before version 1.16.6. crypto/tls
clients can panic when provided a certificate of the wrong type for the
negotiated parameters. net/http clients performing HTTPS requests are
also affected. The panic can be triggered by an attacker in a
privileged network position without access to the server certificate's
private key, as long as a trusted ECDSA or Ed25519 certificate for the
server exists (or can be issued), or the client is configured with
Config.InsecureSkipVerify. Clients that disable all TLS_RSA cipher
suites (that is, TLS 1.0–1.2 cipher suites without ECDHE), as well as
TLS 1.3-only clients, are unaffected.

Impact
======

A man-in-the-middle attacker able to intercept a TLS negotiation could
crash a TLS client by injecting a crafted invalid certificate.

References
==========

https://groups.google.com/g/golang-announce/c/n9FxMelZGAQ...
https://github.com/golang/go/issues/47143
https://github.com/golang/go/commit/58bc454a11d4b3dbc03f4...
https://security.archlinux.org/CVE-2021-34558