CVE-2021-23343Public exploitNetwork attack vector

Service interruption via polynomial regex backtracking

Published May 4, 2021 · Updated Sep 16, 2024

Regular expression denial of service in Javier Blanco path-parse before 1.0.7 allows attackers to interrupt processing via a crafted path. The splitDeviceRe, splitTailRe, and splitPathRe patterns apply overlapping, minimally constrained matches to untrusted path text, producing polynomial backtracking on long invalid strings. Reachability requires a consuming application to pass attacker-controlled paths to the library; exploitation monopolizes its JavaScript execution thread.

CVSS severity7.5
High
EPSS probability2.22%
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 Javier Blanco path-parse before 1.0.7 allows attackers to interrupt processing via a crafted path. The splitDeviceRe, splitTailRe, and splitPathRe patterns apply overlapping, minimally constrained matches to untrusted path text, producing polynomial backtracking on long invalid strings. Reachability requires a consuming application to pass attacker-controlled paths to the library; exploitation monopolizes its JavaScript execution thread.

The record

CVE
CVE-2021-23343
Published
May 4, 2021
Updated
Sep 16, 2024
Vendor
Javier Blanco
Product
path-parse
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Javier Blanco · path-parseversion=0 <unspecified

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.

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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 exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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