CVE-2021-41817

Exp

Date.parse in the date gem through 3.2.0 for Ruby allows ReDoS (regular expression Denial of Service) via a long string. The fixed versions are 3.2.1, 3.1.2, 3.0.2, and 2.0.1.

Published: 2022-01-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-41817 is rated High Exploit Risk (78/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.22%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.73% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-41817

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-41817

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.50% 3.22% +2.73%
2 2026-03-04 0.33% 0.50% +0.16%
3 2026-03-01 — 0.33% —

Full EPSS history (39 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41817

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-41817

GitHub Security Advisory for CVE-2021-41817

GHSA-qg54-694p-wgpp · Severity: high · Ecosystem: rubygems — Regular expression denial of service vulnerability (ReDoS) in date

OS Trackers for CVE-2021-41817

vendor priority summary link
alpine — CVE-2021-41817: 1 source package rows (ruby); 35 state rows across 8 repos (3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 27. https://security.alpinelinux.org/vuln/CVE-2021-41817
debian not yet assigned CVE-2021-41817 not yet assigned priority: Debian including 1 source packages (ruby2.7), 1 status rows across 1 suites (bullseye): resolved 1. https://security-tracker.debian.org/tracker/CVE-2021-41817
gentoo normal CVE-2021-41817: 1 GLSA(s) (202401-27), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-41817
redhat medium — https://access.redhat.com/security/cve/CVE-2021-41817
suse medium CVE-2021-41817 severity moderate: SUSE including 356 source package names (2.17-17.3:libruby2_5-2_5-2.5.9-150000.4.29.1, 2.17-17.3:ruby2.5-2.5.9-150000.4.29.1, …), 1143 product×package rows across 249 product lines (Container bci/ruby, Container suse/rmt-server, … (249 product lines)): Fixed 867, Known Affected 184, Known Not Affected 68, Will Not Fix 24. https://www.suse.com/security/cve/CVE-2021-41817/
ubuntu medium CVE-2021-41817 medium priority: Ubuntu including 4 source packages (ruby2.3, ruby2.5, ruby2.7, ruby3.0), 17 status rows across 8 suites (bionic, focal, hirsute, impish, jammy, trusty, upstream, xenial): ignored 7, released 6, needs-triage 4. https://ubuntu.com/security/CVE-2021-41817

Affected software / configurations for CVE-2021-41817

Vendor Product Version Raw CPE
ruby-lang date < 2.0.1 cpe:2.3:a:ruby-lang:date:*:*:*:*:*:ruby:*:*
ruby-lang date >= 3.0.0, < 3.0.2 cpe:2.3:a:ruby-lang:date:*:*:*:*:*:ruby:*:*
ruby-lang date >= 3.1.0, < 3.1.2 cpe:2.3:a:ruby-lang:date:*:*:*:*:*:ruby:*:*
ruby-lang date 3.2.0 cpe:2.3:a:ruby-lang:date:3.2.0:*:*:*:*:ruby:*:*
ruby-lang ruby >= 2.6.0, < 2.6.9 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 2.7.0, < 2.7.5 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
ruby-lang ruby >= 3.0.0, < 3.0.3 cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
redhat software_collections — cpe:2.3:a:redhat:software_collections:-:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
suse linux_enterprise 12.0 cpe:2.3:o:suse:linux_enterprise:12.0:*:*:*:*:*:*:*
suse linux_enterprise 15.0 cpe:2.3:o:suse:linux_enterprise:15.0:*:*:*:*:*:*:*
opensuse factory — cpe:2.3:a:opensuse:factory:-:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*

References for CVE-2021-41817

cvelogic Threat Intelligence