pycares is a Python module which provides an interface to c-ares. c-ares is a C library that performs DNS requests and name resolutions asynchronously. Prior to version 4.9.0, pycares is vulnerable to a use-after-free condition that occurs when a Channel object is garbage collected while DNS queries are still pending. This results in a fatal Python error and interpreter crash. The vulnerability has been fixed in pycares 4.9.0 by implementing a safe channel destruction mechanism.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in pycares
### Impact
pycares versions < 4.2.0 are affected by [CVE-2021-3672](https://nvd.nist.gov/vuln/detail/CVE-2021-3672).
### Patches
Update to version 4.2.0.