Vulnerability Monitor

The vendors, products, and vulnerabilities you care about

CVE-2021-41819

CGI::Cookie.parse in Ruby through 2.6.8 mishandles security prefixes in cookie names. This also affects the CGI gem through 0.3.0 for Ruby.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts integrity (unauthorized modifications), for affected systems. Impacting 9 products from ruby-lang, from ruby-lang, from redhat and 6 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2022, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2022-01-01T06:15:07.293

Last Modified

2025-05-22T15:15:54.060

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:P/A:N

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

10.0

Impact Score

2.9

Weaknesses

Type: Primary
CWE-565
Type: Secondary
CWE-565

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	ruby-lang	cgi	0.1.0	Yes
Application	ruby-lang	cgi	0.2.0	Yes
Application	ruby-lang	cgi	0.3.0	Yes
Application	ruby-lang	ruby	≤ 2.6.8	Yes
Application	ruby-lang	ruby	< 2.7.5	Yes
Application	ruby-lang	ruby	< 3.0.3	Yes
Application	redhat	software_collections	-	Yes
Operating System	redhat	enterprise_linux	8.0	Yes
Operating System	debian	debian_linux	9.0	Yes
Operating System	debian	debian_linux	10.0	Yes
Operating System	debian	debian_linux	11.0	Yes
Operating System	suse	linux_enterprise	11.0	Yes
Operating System	suse	linux_enterprise	12.0	Yes
Operating System	suse	linux_enterprise	15.0	Yes
Application	opensuse	factory	-	Yes
Operating System	opensuse	leap	15.2	Yes
Operating System	fedoraproject	fedora	34	Yes
Operating System	fedoraproject	fedora	35	Yes

References

https://hackerone.com/reports/910552 Permissions Required, Third Party Advisory ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/ ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/ ([email protected])
https://security.gentoo.org/glsa/202401-27 ([email protected])
https://security.netapp.com/advisory/ntap-20220121-0003/ Third Party Advisory ([email protected])
https://www.ruby-lang.org/en/news/2021/11/24/cookie-prefix-spoofing-in-cgi-cookie-parse-cve-2021-41819/ Exploit, Vendor Advisory ([email protected])
https://hackerone.com/reports/910552 Permissions Required, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/ (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/ (af854a3a-2127-422b-91ae-364da2661108)
https://security.gentoo.org/glsa/202401-27 (af854a3a-2127-422b-91ae-364da2661108)
https://security.netapp.com/advisory/ntap-20220121-0003/ Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://www.ruby-lang.org/en/news/2021/11/24/cookie-prefix-spoofing-in-cgi-cookie-parse-cve-2021-41819/ Exploit, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For ruby-lang's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.