CVE-2024-0450 is a vulnerability in the CPython zipfile module affecting multiple Python versions including 3.8.18 through 3.12.1 and earlier. The issue arises from the zipfile module's improper handling of zip archives containing overlapping entries, a technique known as a 'quoted-overlap' zip-bomb. Zip-bombs are maliciously crafted compressed files that exploit compression algorithms to expand massively upon decompression, overwhelming system resources such as CPU, memory, and disk space. This specific variant leverages overlapping file entries within the zip archive to achieve a high compression ratio, making detection and mitigation more difficult. When a vulnerable Python application processes such a zip file, it can lead to denial of service (DoS) by exhausting resources, potentially causing application crashes or system instability. The vulnerability does not allow for unauthorized data access or modification, focusing its impact solely on availability. Exploitation requires an attacker to supply a malicious zip file to an application using the vulnerable zipfile module, with no authentication or user interaction needed. The Python Software Foundation addressed this vulnerability by updating the zipfile module to reject zip archives with overlapping entries, effectively preventing this attack vector. No known exploits are currently in the wild, but the medium CVSS score of 6.2 reflects the significant availability impact and ease of exploitation. This vulnerability is classified under CWE-405, which relates to improper initialization leading to resource exhaustion or similar issues.

For European organizations, the primary impact of CVE-2024-0450 is denial of service, which can disrupt critical applications that rely on Python's zipfile module to process compressed data. Industries such as finance, healthcare, government, and technology that use Python for data processing, automation, or web services may experience service outages or degraded performance if targeted with malicious zip files. This can lead to operational downtime, loss of productivity, and potential reputational damage. Since the vulnerability does not compromise confidentiality or integrity, data breaches are not a direct concern; however, availability issues can indirectly affect business continuity and compliance with service-level agreements. Organizations that accept or process user-uploaded zip files or integrate third-party data feeds compressed in zip format are particularly at risk. The vulnerability's ease of exploitation without authentication increases the threat surface, especially in environments where untrusted data is handled. European entities with extensive Python usage in software development, cloud services, and automation are more exposed. The lack of known active exploits reduces immediate risk but does not eliminate the potential for future attacks.

To mitigate CVE-2024-0450, European organizations should prioritize upgrading to the fixed CPython versions where the zipfile module rejects overlapping zip entries. Specifically, updating to versions beyond 3.12.1, 3.11.7, 3.10.13, 3.9.18, or 3.8.18 is essential. For environments where immediate upgrading is not feasible, implement additional validation layers to inspect zip files for overlapping entries or abnormal compression ratios before processing. Employ sandboxing or resource-limiting techniques when decompressing zip files to contain potential resource exhaustion. Incorporate monitoring and alerting for unusual CPU, memory, or disk usage spikes during file processing. Educate developers and system administrators about the risks of processing untrusted zip files and enforce strict input validation policies. Where possible, restrict the acceptance of zip files from untrusted or anonymous sources. Finally, maintain an incident response plan to quickly address denial of service conditions arising from malicious file processing.