CVE-2020-15523

mediumpriority · track · 31EPSS 0.009 · 61 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.95% (61st) EPSS

CVSS 6.9 · medium

Is it mine?

60 products

Check your exposure

Who says so?

7 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4rc1, and 3.9 through 3.9.0b4 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Only build and run applications from trusted sources.

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.8

v2.06.9mediumAV:L/AC:M/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 3.4 · impact 10

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:Csecondary · CISA US

v3.17.8highAV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE

v3.17.1highCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-427USprimaryCWE-908USprimaryCWE-427USCWE-427USCWE-427USCWE-908US

affected products (60)

Products and version ranges known to be affected.

Open Source Python <3.8.5all versionscert_bundDE
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Open Source Python< 3.8.5cert_bundDE
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)all versionscisa_csaf_otUS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)all versionscisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
n/a n/a≤ n/aenisa_euvdEU
Python Software Foundation Python≤ 3.9.0 beta4fstec_bduRU
Python Software Foundation Python≤ 3.9.0 beta3fstec_bduRU
Python Software Foundation Python≤ 3.9.0 beta2fstec_bduRU
Python Software Foundation Python≤ 3.9.0 beta1fstec_bduRU
Python Software Foundation Python≤ 3.9.0 alpha6fstec_bduRU

showing 20 of 60

advisories (7)

Vendor and ecosystem advisories describing this.

SSA-398330SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.52023-12-12csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 are no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 (https://cert-portal.siemens.com/productcert/html/ssb-439005.html).
WID-SEC-W-2025-1235Python: Schwachstelle ermöglicht Umgehen von SicherheitsvorkehrungenDeutsch2020-07-20csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle in Python ausnutzen, um Sicherheitsvorkehrungen zu umgehen.
ICSA-23-348-10Siemens SIMATIC S7-15002023-12-12icsa · cisa_csaf_otUS
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).
BIT-libpython-2020-155232025-08-11vendor · osvUS
In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4, and 3.9 through 3.9.0 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.
BIT-python-2020-155232024-03-06vendor · osvUS
In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4, and 3.9 through 3.9.0 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.
BIT-python-min-2020-155232025-01-16vendor · osvUS
In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4, and 3.9 through 3.9.0 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.
PSF-2020-4Py_SetPath(): _Py_CheckPython3 uses uninitialized DLL path2020-07-04vendor · osvUS
In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4rc1, and 3.9 through 3.9.0b4 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.

also known as (8)

Other names and identifiers for this entity.

CNNVD-202007-231 cnnvd
EUVD-2020-7510 enisa_euvd
BDU:2024-09235 fstec_bdu
GHSA-mj5j-j2qm-c8g4 enisa_euvd
BIT-libpython-2020-15523osv
BIT-python-2020-15523osv
BIT-python-min-2020-15523osv
PSF-2020-4osv

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund cisa_csaf_ot siemens_psirt NVD CVE.org MITRE

published 2020-07-04modified 2026-06-17

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+2446 more

references (14)

External citations — patches, advisories, analysis.

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