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CVE-2021-33502

24
FAUCET Score

CVE-2021-33502 is a Regular Expression Denial of Service (ReDoS) vulnerability affecting the normalize-url Node.js package in versions prior to 4.5.1, 5.3.1, and 6.0.1. This flaw, rated 7.5 HIGH on the CVSS scale, stems from exponential performance when processing specially crafted data: URLs, leading to a denial of service. While the attack vector is network-based with low complexity and no user interaction required, there is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this vulnerability.

Impacted Technologies

VendorProductVersion(s)CPE
>= 4.3.0, < 4.5.1CPE matchmatch criteria
cpe:2.3:a:normalize-url_project:normalize-url:*:*:*:*:*:node.js:*:*
>= 5.0.0, < 5.3.1CPE matchmatch criteria
cpe:2.3:a:normalize-url_project:normalize-url:*:*:*:*:*:node.js:*:*
6.0.0CPE matchmatch criteria
cpe:2.3:a:normalize-url_project:normalize-url:6.0.0:*:*:*:*:node.js:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.70%
Probability of exploitation in next 30 days
EPSS Percentile
74.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0170 is in the 57th percentile among its peer group of 51,506 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (21)

npmpatch availablevia ghsa
Product: normalize-urlFixed in: 4.5.1
npmpatch availablevia ghsa
Product: normalize-urlFixed in: 6.0.1
npmpatch availablevia ghsa
Product: normalize-urlFixed in: 5.3.1
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8.4 Extended Update SupportFixed in: nodejs:14-8040020211213111158.522a0ee4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: nodejs-nodemon-0:2.0.19-1.el9_0
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-nodejs12-nodejs-0:12.22.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-nodejs12-nodejs-nodemon-0:2.0.3-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-nodejs14-nodejs-0:14.17.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-nodejs12-nodejs-0:12.22.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-nodejs12-nodejs-nodemon-0:2.0.3-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-nodejs14-nodejs-0:14.17.2-1.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUSFixed in: rh-nodejs14-nodejs-nodemon-0:2.0.3-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Virtualization Engine 4.4Fixed in: ovirt-engine-ui-extensions-0:1.3.3-1.el8ev
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Virtualization Engine 4.4Fixed in: ovirt-web-ui-0:1.8.1-2.el8ev
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-nodejs14-nodejs-nodemon-0:2.0.3-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: nodejs:16-8050020211206113934.c5368500
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: nodejs:14-8050020211213115342.c5368500
View patch
redhatvendor investigatingvia redhat_api
Product: Red Hat Advanced Cluster Management for Kubernetes 2Fixed in: rhacm2/mcm-topology-api-rhel8
redhatvendor investigatingvia redhat_api
Product: Red Hat Advanced Cluster Management for Kubernetes 2Fixed in: rhacm2/search-ui-rhel8
redhatno patchvia redhat_api
Product: Red Hat Advanced Cluster Management for Kubernetes 2Fixed in: rhacm2/search-api-rhel8
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: nodejs:12/nodejs-nodemon

Vendor Advisories (2)

npmGHSA-px4h-xg32-q955high

ReDoS in normalize-url

Jun 8, 2021
redhatCVE-2021-33502Moderate

nodejs-normalize-url: ReDoS for data URLs

May 21, 2021

References

github.com / sindresorhus/normalize-url/releases/tag/v6.0.1
Release NotesThird Party Advisory
security.netapp.com / advisory/ntap-20210706-0001
Third Party Advisory