CVE-2021-32066

Description

An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an 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."

How to fix CVE-2021-32066

To remediate CVE-2021-32066, upgrade the affected package to a fixed version below.

• —upgrade to 2.6.8-r0 or later
• —upgrade to 2.6.8 or later
• —upgrade to 2.6.8 or later
• —upgrade to 9.3.9.0+ds-1 or later
• —upgrade to 2.7.4-1 or later

Is CVE-2021-32066 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (5)

• from 0, < 2.6.8-r0
• >= 2.6.0, < 2.6.8, >= 2.7.0, < 2.7.4, >= 3.0.0, < 3.0.2
• >= 2.6.0, < 2.6.8, >= 2.7.0, < 2.7.4, >= 3.0.0, < 3.0.2
• from 0, < 9.3.9.0+ds-1
• from 0, < 2.7.4-1

CVSS scores

References (11)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-32066
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-32066
• WEBgithub.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a
• WEBhackerone.com/reports/1178562