CVE-2021-21001Network attack vector

Authenticated file disclosure via path traversal

Published May 24, 2021 · Updated Sep 16, 2024

Path traversal in the CODESYS 2.3 Runtime on affected WAGO controllers allows remote authenticated users to read protected files. The runtime accepts crafted packet pathnames without confining filesystem resolution to the authenticated user's permitted directory. Network access and valid credentials are required; public records establish unauthorized file access but do not identify writable paths or code execution.

CVSS severity9.1
Critical
EPSS probability1.13%
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 the CODESYS 2.3 Runtime on affected WAGO controllers allows remote authenticated users to read protected files. The runtime accepts crafted packet pathnames without confining filesystem resolution to the authenticated user's permitted directory. Network access and valid credentials are required; public records establish unauthorized file access but do not identify writable paths or code execution.

The record

CVE
CVE-2021-21001
Published
May 24, 2021
Updated
Sep 16, 2024
Vendor
WAGO
Product
PFC200 Controller
Classifications
CWE-22, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 24, 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=750-823 <=FW07
  2. Affected versionversion=750-829 <=FW14
  3. Affected versionversion=750-831/000-00x <=FW14
  4. Affected versionversion=750-832/000-00x <=FW06
  5. Affected versionversion=750-852 <=FW14
  6. Affected versionversion=750-862 <=FW07
  7. Affected versionversion=750-880/0xx-xxx <=FW15
  8. Affected versionversion=750-881 <=FW14
  9. Affected versionversion=750-882 <=FW14
  10. Affected versionversion=750-885/0xx-xxx <=FW14
  11. Affected versionversion=750-889 <=FW14
  12. Affected versionversion=750-890/0xx-xxx <=FW07
  13. Affected versionversion=750-891 <=FW07
  14. Affected versionversion=750-893 <=FW07

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

WAGO · PFC200 Controllerversion=750-823 <=FW07; version=750-829 <=FW14; version=750-831/000-00x <=FW14; version=750-832/000-00x <=FW06; version=750-852 <=FW14; version=750-862 <=FW07; version=750-880/0xx-xxx <=FW15; version=750-881 <=FW14; version=750-882 <=FW14; version=750-885/0xx-xxx <=FW14; version=750-889 <=FW14; version=750-890/0xx-xxx <=FW07; version=750-891 <=FW07; version=750-893 <=FW07
WAGO · Series 750 Ethernet Controllerversion=750-8202/xxx-xxx <03.06.19 (18); version=750-8203/xxx-xxx <03.06.19 (18); version=750-8204/xxx-xxx <03.06.19 (18); version=750-8206/xxx-xxx <03.06.19 (18); version=750-8207/xxx-xxx <03.06.19 (18); version=750-8208/xxx-xxx <03.06.19 (18); version=750-8210/xxx-xxx <03.06.19 (18); version=750-8211/xxx-xxx <03.06.19 (18); version=750-8212/xxx-xxx <03.06.19 (18); version=750-8213/xxx-xxx <03.06.19 (18); version=750-8214/xxx-xxx <03.06.19 (18); version=750-8216/xxx-xxx <03.06.19 (18); version=750-8217/xxx-xxx <03.06.19 (18)

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
9.1CERT VDECVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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

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Your stack

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