CVE-2021-40364

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). The affected systems store sensitive information in log files. An attacker with access to the log files could publicly expose the information or reuse it to develop further attacks on the system.

Published: 2021-11-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-40364 is rated Low Risk (27/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.23%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-40364

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 0.13% 0.23% +0.10%
2 2025-03-30 0.21% 0.13% -0.08%
3 2025-03-29 — 0.21% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-40364

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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.
 1.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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.
 1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-40364

Affected software / configurations for CVE-2021-40364

Vendor Product Version Raw CPE
siemens simatic_pcs_7 <= 8.2 cpe:2.3:a:siemens:simatic_pcs_7:*:*:*:*:*:*:*:*
siemens simatic_pcs_7 >= 9.0, < 9.1 cpe:2.3:a:siemens:simatic_pcs_7:*:*:*:*:*:*:*:*
siemens simatic_pcs_7 9.1 cpe:2.3:a:siemens:simatic_pcs_7:9.1:-:*:*:*:*:*:*
siemens simatic_wincc <= 7.4 cpe:2.3:a:siemens:simatic_wincc:*:*:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:-:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp1:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp1_update1:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp1_update2:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp2:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update1:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update2:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update3:*:*:*:*:*:*
siemens simatic_wincc 7.5 cpe:2.3:a:siemens:simatic_wincc:7.5:sp2_update4:*:*:*:*:*:*
siemens simatic_wincc 15 cpe:2.3:a:siemens:simatic_wincc:15:*:*:*:*:*:*:*
siemens simatic_wincc 16 cpe:2.3:a:siemens:simatic_wincc:16:-:*:*:*:*:*:*
siemens simatic_wincc 16 cpe:2.3:a:siemens:simatic_wincc:16:update1:*:*:*:*:*:*
siemens simatic_wincc 16 cpe:2.3:a:siemens:simatic_wincc:16:update2:*:*:*:*:*:*
siemens simatic_wincc 16 cpe:2.3:a:siemens:simatic_wincc:16:update3:*:*:*:*:*:*
siemens simatic_wincc 16 cpe:2.3:a:siemens:simatic_wincc:16:update4:*:*:*:*:*:*
siemens simatic_wincc 17 cpe:2.3:a:siemens:simatic_wincc:17:-:*:*:*:*:*:*
siemens simatic_wincc 17 cpe:2.3:a:siemens:simatic_wincc:17:update1:*:*:*:*:*:*

References for CVE-2021-40364

cvelogic Threat Intelligence