Adding Apache Airflow vulnerability checks

[adambakalar]

Adding vulnerability checks for the following Apache Airflow CVEs:

• CVE-2020-11978
• CVE-2020-13927
• CVE-2020-17526

Jira ticket for more details: https://intriguesecurity.atlassian.net/browse/COR-104

One note:

When working on the vulnerability task for CVE-2020-17526 I tried making it work with both the NetworkService and Uri entity types, but when testing with the Uri type Core was never able to properly grab the fingerprint detail, even though when I looked up the entity itself the fingerprints were there, including the Apache Airflow fingerprint.

[adambakalar]

After speaking with @shpendk I pushed some changes to the vuln checks:

CVE-2020-11978:

• Removed the first 2 requests from the nuclei template cause they are not really needed

CVE-2020-17526:

• In the issue details I changed status to potential from confirmed: Since this check is based on a version check Shpend requested this change
• Put in require_enrichment at the start of the check, that will make it work with the Uri entity type, so I removed the NetworkService entity type.