CVE-2020-9947 is a vulnerability that was discovered in the Python standard library's email package. This vulnerability allows an attacker to exploit the library's lack of validation on certain email addresses, which can lead to a denial-of-service (DoS) attack. When exploited, this vulnerability can cause the Python application using the email package to crash or become unresponsive, potentially resulting in data loss or other adverse effects.
The vulnerability was first reported to the Python Software Foundation's security team on February 11, 2020. The team then worked with the reporter to identify and fix the vulnerability, releasing a patch on February 20, 2020. The patch addressed the issue by improving the validation of email addresses, preventing malicious inputs from causing a DoS attack.
In order to prevent potential exploitation of this vulnerability, it is recommended that Python users update their installations to the latest version of the email package. Additionally, users are advised to be cautious when processing email addresses, and to implement additional input validation checks where necessary to further reduce the risk of DoS attacks.