A ruby security update has been released for Arch Linux.

ASA-202107-23: ruby: multiple issues

Arch Linux Security Advisory ASA-202107-23
==========================================

Severity: High
Date : 2021-07-14
CVE-ID : CVE-2021-31810 CVE-2021-32066
Package : ruby
Type : multiple issues
Remote : Yes
Link :   https://security.archlinux.org/AVG-2138

Summary
=======

The package ruby before version 3.0.2-1 is vulnerable to multiple
issues including silent downgrade and information disclosure.

Resolution
==========

Upgrade to 3.0.2-1.

# pacman -Syu "ruby>=3.0.2-1"

The problems have been fixed upstream in version 3.0.2.

Workaround
==========

None.

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

- CVE-2021-31810 (information disclosure)

A security issue has been discovered in Ruby before versions 3.0.2,
2.7.4 and 2.6.8. A malicious FTP server can use the PASV response to
trick Net::FTP into connecting back to a given IP address and port.
This potentially makes Net::FTP extract information about services that
are otherwise private and not disclosed (e.g., the attacker can conduct
port scans and service banner extractions).

- CVE-2021-32066 (silent downgrade)

A security issue has been discovered in Ruby before versions 3.0.2,
2.7.4 and 2.6.8. Net::IMAP does not raise an exception when StartTLS
fails with an unknown response, which might allow man-in-the-middle
attackers to bypass the TLS protections by leveraging a network
position between the client and the registry to block the StartTLS
command, aka a “StartTLS stripping attack”.

Impact
======

A remote man-in-the-middle attacker could strip StartTLS encryption
from IMAP connections to disclose authentication credentials and
emails. Furthermore, a malicious FTP server could induce connections to
an arbitrary IP address and port on a client, leading to potential
information disclosure.

References
==========

  https://www.ruby-lang.org/en/news/2021/07/07/trusting-pasv-responses-in-net-ftp/
  https://hackerone.com/reports/1145454
  https://github.com/ruby/net-ftp/commit/5709ece67cf57a94655e34532f8a7899b28d496a
  https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/
  https://hackerone.com/reports/1178562
  https://github.com/ruby/net-imap/commit/adba6f0c3e5c5607c4822b9120322eb7e9a77891
  https://security.archlinux.org/CVE-2021-31810
  https://security.archlinux.org/CVE-2021-32066