Improper Input Validation
When the Elastic APM agent for Python versions before 5.1.0 is run as a CGI script, there is a variable name clash flaw if a remote attacker can control the proxy header. This could result in an attacker redirecting collected APM data to a proxy of their choosing.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.