CVE-2021-23362Network attack vector

Service interruption via polynomial shortcut URL matching

Published Mar 23, 2021 · Updated Sep 17, 2024

Regular expression denial of service in npm hosted-git-info before 3.0.8 allows remote attackers to interrupt service via crafted repository URLs. The fromUrl function applies the nested, ambiguous shortcutMatch expression in index.js to an entire untrusted URL, producing polynomial worst-case matching time. Exploitation requires a consuming application to pass attacker-controlled repository strings to this API and can exhaust its processing capacity.

CVSS severity5.3
Medium
EPSS probability3.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in npm hosted-git-info before 3.0.8 allows remote attackers to interrupt service via crafted repository URLs. The fromUrl function applies the nested, ambiguous shortcutMatch expression in index.js to an entire untrusted URL, producing polynomial worst-case matching time. Exploitation requires a consuming application to pass attacker-controlled repository strings to this API and can exhaust its processing capacity.

The record

CVE
CVE-2021-23362
Published
Mar 23, 2021
Updated
Sep 17, 2024
Vendor
npm
Product
hosted-git-info
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <3.0.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

npm · hosted-git-infoversion=unspecified <3.0.8

Published CVSS scores

5.3SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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