CVE-2021-23357Public exploitNetwork attack vector

Authenticated JSON overwrite via APIID traversal

Published Mar 15, 2021 · Updated Sep 17, 2024

Path traversal in Tyk Gateway allows remote authenticated users to overwrite arbitrary JSON files through the management API. The handleAddOrUpdateApi function uses the caller-controlled APIID as a file path, deletes any same-named JSON file, and recreates it with the submitted API definition. Access requires the shared-secret management interface, and successful exploitation is limited to JSON files writable by the gateway process.

CVSS severity5.3
Medium
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Tyk Gateway allows remote authenticated users to overwrite arbitrary JSON files through the management API. The handleAddOrUpdateApi function uses the caller-controlled APIID as a file path, deletes any same-named JSON file, and recreates it with the submitted API definition. Access requires the shared-secret management interface, and successful exploitation is limited to JSON files writable by the gateway process.

The record

CVE
CVE-2021-23357
Published
Mar 15, 2021
Updated
Sep 17, 2024
Vendor
Tyk Technologies
Product
Tyk Gateway
Classifications
CWE-22, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 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?

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  1. Affected versionversion=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Tyk Technologies · Tyk Gatewayversion=0 <unspecified

Published CVSS scores

3.3SnykCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
5.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1565.001Stored Data Manipulation

Public exploit references

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Technologies

Your stack

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Your stack

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