CVE-2021-41819
HIGH
7.5
CVSS Score
Published: January 1, 2022 at 12:00 AM UTC
Updated: June 17, 2026 at 04:08 AM UTC
9 products affected across 6 vendorsDebian LinuxFedoraEnterprise Linux
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Severity
HIGH7.5
Exploit prediction
EPSS 3%
SSVC
No known exploit
Description
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.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Debian Linux· Debiandrupal
95%All versions
Leap· openSUSEdrupal
95%All versions
Cgi· Ruby Langrubygems
95%Ruby· Ruby Langrubygems
95%v ≤ 2.6.82.7.0 ≤ v < 2.7.53.0.0 ≤ v < 3.0.3
Affected range stops below 2.7.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.0.3, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IUXQCH6FRKANCVZO2Q7D2SQX33FP3KWN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UTOJGS5IEFDK3UOO7IY4OTTFGHGLSWZF/
- https://security.gentoo.org/glsa/202401-27
- https://www.ruby-lang.org/en/news/2021/11/24/cookie-prefix-spoofing-in-cgi-cookie-parse-cve-2021-41819/
References (6)
Permissions RequiredThird Party Advisory
Source: [email protected]
https://hackerone.com/reports/910552Third Party Advisory
Source: [email protected]
https://security.netapp.com/advisory/ntap-20220121-0003/ExploitVendor Advisory
Source: [email protected]
https://www.ruby-lang.org/en/news/2021/11/24/cookie-prefix-spoofing-in-cgi-cookie-parse-cve-2021-41819/SSVC — Action Prioritization
SSVCNo known exploitNot automatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
7.5HIGHCISA-ADP
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- HIGH
- Availability
- NONE
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-565
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