CVE-2021-33621

Description

The cgi gem before 0.1.0.2, 0.2.x before 0.2.2, and 0.3.x before 0.3.5 for Ruby allows HTTP response splitting. This is relevant to applications that use untrusted user input either to generate an HTTP response or to create a CGI::Cookie object.

How to fix CVE-2021-33621

To remediate CVE-2021-33621, upgrade the affected package to a fixed version below.

• Alpine/ruby—upgrade to 2.7.7-r0 or later
• —upgrade to 2.7.7 or later
• —upgrade to 2.7.7 or later
• —upgrade to 2.5.5-3+deb10u6 or later
• —upgrade to 2.7.4-1+deb11u2 or later
• —upgrade to 2.7.4-1+deb11u2 or later
• —upgrade to 3.1.2-4 or later
• —upgrade to 0.3.5 or later

Is CVE-2021-33621 being exploited?

Low — EPSS is 1.1%, meaning exploitation activity has not been observed at scale.

Affected packages (8)

• from 0, < 2.7.7-r0
• >= 2.7.0, < 2.7.7, >= 3.0.0, < 3.0.5, >= 3.1.0, < 3.1.3
• >= 2.7.0, < 2.7.7, >= 3.0.0, < 3.0.5, >= 3.1.0, < 3.1.3
• from 0, < 2.5.5-3+deb10u6
• from 0, < 2.7.4-1+deb11u2
• from 0, < 2.7.4-1+deb11u2
• from 0, < 3.1.2-4
• >= 0.3.0, < 0.3.5

CVSS scores

References (21)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-33621
• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-33621
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-33621
• WEBgithub.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2021-33621.yml