CVE-2021-23384Public exploitNetwork attack vector

Open redirect via protocol-relative request paths

Published May 17, 2021 · Updated Sep 16, 2024

Open redirect in Verdens Gang AS koa-remove-trailing-slashes before 2.0.2 allows remote attackers to redirect users via crafted request paths. The removeTrailingSlashes function passed a leading double-slash path and query directly to ctx.redirect without verifying that the destination retained the request origin. Exploitation requires a user to request an affected endpoint and follow its redirect, enabling navigation to an attacker-controlled origin.

CVSS severity5.4
Medium
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in Verdens Gang AS koa-remove-trailing-slashes before 2.0.2 allows remote attackers to redirect users via crafted request paths. The removeTrailingSlashes function passed a leading double-slash path and query directly to ctx.redirect without verifying that the destination retained the request origin. Exploitation requires a user to request an affected endpoint and follow its redirect, enabling navigation to an attacker-controlled origin.

The record

CVE
CVE-2021-23384
Published
May 17, 2021
Updated
Sep 16, 2024
Vendor
Verdens Gang AS
Product
koa-remove-trailing-slashes
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 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 <2.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Verdens Gang AS · koa-remove-trailing-slashesversion=unspecified <2.0.2

Published CVSS scores

4.9Snyk CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C
5.4GitHub Advisory DatabaseCVSS: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.

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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-601URL Redirection to Untrusted Site ('Open Redirect')
T1204.001User Execution: Malicious Link

Public exploit references

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

Technologies

Your stack

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Your stack

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