CVE-2021-21001 | WAGO: PFC200 Access to files outside the home directory

On WAGO PFC200 devices in different firmware versions with special crafted packets an authorised attacker with network access to the device can access the file system with higher privileges.

Published: 2021-05-24 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-21001 is rated Moderate Risk (59.1/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.13%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-21001

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.24% 1.13% +0.90%
2 2025-07-22 0.32% 0.24% -0.08%
3 2025-03-30 — 0.32% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21001

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.3 6.0 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-21001

Affected software / configurations for CVE-2021-21001

Vendor Product Version Raw CPE
wago 750-823_firmware < fw08 cpe:2.3:o:wago:750-823_firmware:*:*:*:*:*:*:*:*
wago 750-829_firmware < fw15 cpe:2.3:o:wago:750-829_firmware:*:*:*:*:*:*:*:*
wago 750-831_firmware < fw15 cpe:2.3:o:wago:750-831_firmware:*:*:*:*:*:*:*:*
wago 750-832_firmware < fw08 cpe:2.3:o:wago:750-832_firmware:*:*:*:*:*:*:*:*
wago 750-852_firmware < fw15 cpe:2.3:o:wago:750-852_firmware:*:*:*:*:*:*:*:*
wago 750-862_firmware < fw08 cpe:2.3:o:wago:750-862_firmware:*:*:*:*:*:*:*:*
wago 750-880_firmware < fw16 cpe:2.3:o:wago:750-880_firmware:*:*:*:*:*:*:*:*
wago 750-881_firmware < fw15 cpe:2.3:o:wago:750-881_firmware:*:*:*:*:*:*:*:*
wago 750-882_firmware < fw15 cpe:2.3:o:wago:750-882_firmware:*:*:*:*:*:*:*:*
wago 750-885_firmware < fw15 cpe:2.3:o:wago:750-885_firmware:*:*:*:*:*:*:*:*
wago 750-889_firmware < fw15 cpe:2.3:o:wago:750-889_firmware:*:*:*:*:*:*:*:*
wago 750-890_firmware < fw08 cpe:2.3:o:wago:750-890_firmware:*:*:*:*:*:*:*:*
wago 750-891_firmware < fw08 cpe:2.3:o:wago:750-891_firmware:*:*:*:*:*:*:*:*
wago 750-893_firmware < fw08 cpe:2.3:o:wago:750-893_firmware:*:*:*:*:*:*:*:*
wago 750-8202_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8202_firmware:*:*:*:*:*:*:*:*
wago 750-8203_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8203_firmware:*:*:*:*:*:*:*:*
wago 750-8204_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8204_firmware:*:*:*:*:*:*:*:*
wago 750-8206_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8206_firmware:*:*:*:*:*:*:*:*
wago 750-8207_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8207_firmware:*:*:*:*:*:*:*:*
wago 750-8208_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8208_firmware:*:*:*:*:*:*:*:*
wago 750-8210_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8210_firmware:*:*:*:*:*:*:*:*
wago 750-8211_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8211_firmware:*:*:*:*:*:*:*:*
wago 750-8212_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8212_firmware:*:*:*:*:*:*:*:*
wago 750-8213_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8213_firmware:*:*:*:*:*:*:*:*
wago 750-8214_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8214_firmware:*:*:*:*:*:*:*:*
wago 750-8216_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8216_firmware:*:*:*:*:*:*:*:*
wago 750-8217_firmware < 03.06.19_\(18\) cpe:2.3:o:wago:750-8217_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-21001

cvelogic Threat Intelligence