CVE-2021-23443Network attack vector

Cross-site scripting via unescaped array template values

Published Sep 21, 2021 · Updated Sep 16, 2024

Type confusion in AdonisJS Edge before 5.3.2 allows remote attackers to inject executable markup by supplying array template values. The escape() path returned arrays unchanged because it escaped only strings, while template interpolation inserted the array's string form into HTML. Exploitation requires an application to pass attacker-controlled arrays into an escaped interpolation and a user to view the rendered page, where injected script runs in that page's origin.

CVSS severity6.1
Medium
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in AdonisJS Edge before 5.3.2 allows remote attackers to inject executable markup by supplying array template values. The escape() path returned arrays unchanged because it escaped only strings, while template interpolation inserted the array's string form into HTML. Exploitation requires an application to pass attacker-controlled arrays into an escaped interpolation and a user to view the rendered page, where injected script runs in that page's origin.

The record

CVE
CVE-2021-23443
Published
Sep 21, 2021
Updated
Sep 16, 2024
Vendor
AdonisJS
Product
Edge
Classifications
CWE-843, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 21, 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=unspecified <5.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

AdonisJS · Edgeversion=unspecified <5.3.2

Published CVSS scores

5.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.4SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

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-843Access of Resource Using Incompatible Type ('Type Confusion')
T1059.007JavaScript/JScript

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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