CVE-2020-8315: Unsafe DLL loading in getpathp.c on Windows 7

At Python startup, api-ms-win-core-path-l1-1-0.dll is loaded with LoadLibraryW() without LOAD_LIBRARY_SEARCH_xxx flags.

Python 3.5 and older are not affected.

  • Disclosure date: 2020-01-21 (Python issue bpo-39401 reported)

Fixed In

Python issue

[CVE-2020-8315] Unsafe dll loading in getpathp.c on Win7.

  • Python issue: bpo-39401
  • Creation date: 2020-01-21
  • Reporter: Anthony Wee

CVE-2020-8315

In Python (CPython) 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1, an insecure dependency load upon launch on Windows 7 may result in an attacker’s copy of api-ms-win-core-path-l1-1-0.dll being loaded and used instead of the system’s copy. Windows 8 and later are unaffected.

Timeline

Timeline using the disclosure date 2020-01-21 as reference: