CVE-2021-20995Network attack vector

Credential disclosure via cleartext web UI cookies

Published May 13, 2021 · Updated Sep 17, 2024

Cleartext credential storage in WAGO managed-switch firmware allows remote attackers to read user credentials from web UI cookies. The embedded web server places authenticated users' credentials directly in browser cookies instead of keeping those secrets out of client-side cookie data. CERT@VDE has not published how remote attackers obtain the cookie; disclosure is limited to its credentials, with no reported write or service impact.

CVSS severity5.3
Medium
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext credential storage in WAGO managed-switch firmware allows remote attackers to read user credentials from web UI cookies. The embedded web server places authenticated users' credentials directly in browser cookies instead of keeping those secrets out of client-side cookie data. CERT@VDE has not published how remote attackers obtain the cookie; disclosure is limited to its credentials, with no reported write or service impact.

The record

CVE
CVE-2021-20995
Published
May 13, 2021
Updated
Sep 17, 2024
Vendor
WAGO
Product
0852-1305 Industrial Managed Switch
Classifications
CWE-312
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=V1.1.7.S0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WAGO · 0852-1305 Industrial Managed Switchversion=unspecified <=V1.1.7.S0
WAGO · 0852-1305/000-001 Industrial Managed Switchversion=unspecified <=V1.0.4.S0
WAGO · 0852-1505 Industrial Managed Switchversion=unspecified <=V1.1.6.S0
WAGO · 0852-0303 Industrial Managed Switchversion=unspecified <=V1.2.3.S0
WAGO · 0852-1505/000-001 Industrial Managed Switchversion=unspecified <=V1.0.4.S0

Published CVSS scores

5.3CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/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-312Cleartext Storage of Sensitive Information

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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