CVE-2022-48565: 
NixOS vulnerability analysis and mitigation

An XML External Entity (XXE) vulnerability (CVE-2022-48565) was discovered in Python through version 3.9.1. The vulnerability affects the plistlib module, which processes XML plist files. The issue was discovered in 2020 and publicly disclosed in August 2023 (NVD, CVE).

The vulnerability exists in the plistlib module's XML processing functionality. To address the security concern, the module no longer accepts entity declarations in XML plist files to prevent XML-based vulnerabilities. The issue has been assigned a CVSS v3.1 base score of 9.8 (Critical) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating a critical severity level with network attack vector, low attack complexity, and no required privileges or user interaction (NetApp).

Successful exploitation of this vulnerability could lead to disclosure of sensitive information, addition or modification of data, or Denial of Service (DoS). The high severity score reflects the potential for significant impact on system confidentiality, integrity, and availability (NetApp).

The vulnerability has been fixed in multiple Python versions through security updates. Various Linux distributions and software vendors have released patches to address this vulnerability. For example, Debian has released fixes for Python 2.7 and Python 3.7, and Fedora has updated their Python packages to address this issue (Debian LTS, Fedora).