CVE-2021-23411Network attack vector

Cross-site scripting via unescaped anchor href

Published Jul 21, 2021 · Updated Sep 16, 2024

Cross-site scripting in Anchorme.js through version 2.1.2 allows remote attackers to execute JavaScript in generated links via crafted input. The transform function inserts input.string directly into an HTML anchor href without escaping, allowing a javascript scheme or other script-bearing value to survive into rendered markup. Exploitation requires a consuming application to process attacker-controlled text and a user to interact with the generated link; impact is script execution in that application’s security context.

CVSS severity6.1
Medium
EPSS probability1.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site scripting in Anchorme.js through version 2.1.2 allows remote attackers to execute JavaScript in generated links via crafted input. The transform function inserts input.string directly into an HTML anchor href without escaping, allowing a javascript scheme or other script-bearing value to survive into rendered markup. Exploitation requires a consuming application to process attacker-controlled text and a user to interact with the generated link; impact is script execution in that application’s security context.

The record

CVE
CVE-2021-23411
Published
Jul 21, 2021
Updated
Sep 16, 2024
Vendor
Alex Corvi
Product
Anchorme.js
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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?

Alex Corvi · Anchorme.jsversion=0 <unspecified

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
5.4GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Reflected Cross-Site Scripting

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo