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Fencer Vulns
high 7.8

CVE-2020-15523 json

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…

published 2020-07-04 6 y ago modified 2026-10-14 25 d ago also BIT-libpython-2020-15523 , BIT-python-2020-15523 , BIT-python-min-2020-15523 , EUVD-2020-7510

cvss
7.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami libpython 3.5.10, 3.6.12, 3.7.9, 3.8.4
  • bitnami python 3.5.10, 3.6.12, 3.7.9, 3.8.4
  • bitnami python-min 3.5.10, 3.6.12, 3.7.9, 3.8.4
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • python311 Linux Micro 6.0 3.11.13-1.1
  • python311-core Linux Micro 6.0 3.11.13-1.1
  • python311 Linux Micro 6.0 3.11.11-1.1
  • python311-core Linux Micro 6.0 3.11.11-1.1
  • python311 Linux Micro 6.0 3.11.8-3.1
  • python311-core Linux Micro 6.0 3.11.8-3.1

suse advisories SUSE-SU-2025:20492-1SUSE-SU-2025:20154-1SUSE-SU-2025:20025-1

  • python315 openSUSE Tumbleweed 3.15.0~a1-1.1
  • python314 openSUSE Tumbleweed 3.14.0~a1-1.1
  • python313 openSUSE Tumbleweed 3.13.0~b3-1.1
  • python310 openSUSE Tumbleweed 3.10.0rc1-4.2
  • python39 openSUSE Tumbleweed 3.9.7-2.1
  • python311 openSUSE Tumbleweed 3.11.0b1-1.1
  • python312 openSUSE Tumbleweed 3.12.0a7-1.1

opensuse advisories openSUSE-SU-2025:15713-1openSUSE-SU-2024:14434-1openSUSE-SU-2024:14109-1openSUSE-SU-2024:11283-1openSUSE-SU-2024:11286-1openSUSE-SU-2024:12089-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-23-348-10 updated cvss 7.8

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
31 d ago

Exploit prediction

0.91% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.9 AV:L/AC:M/Au:N/C:C/I:C/A:C
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
bitnami libpython
>=3.5.0, <3.5.10
>=3.6.0, <3.6.12
>=3.7.0, <3.7.9
>=3.8.0, <3.8.4
3.5.10
3.6.12
3.7.9
3.8.4
bitnami python
>=3.5.0, <3.5.10
>=3.6.0, <3.6.12
>=3.7.0, <3.7.9
>=3.8.0, <3.8.4
3.5.10
3.6.12
3.7.9
3.8.4
bitnami python-min
>=3.5.0, <3.5.10
>=3.6.0, <3.6.12
>=3.7.0, <3.7.9
>=3.8.0, <3.8.4
3.5.10
3.6.12
3.7.9
3.8.4

Affected products

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-427 Uncontrolled Search Path Element
  • CWE-908 Use of Uninitialized Resource

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.