That is not what is being done. If you advertise a route with a corrupt attribute, your route will be considered inaccessible by any device that understands the attribute.
But! All your other routes that you advertised earlier with perfectly fine attributes will continue working. This is what prevents this from becoming a DoS vulnerability.
Let's take a more complete example.
ISP1 advertises 2 routes to ISP2:
35.67.0.0/16 attr1=val1
37.61.0.0/16 attr1=corr
ISP2 doesn't know what attr1 is, and it advertisea the following routes to ISP3:
The bug is that ISP3 will then stop routing any traffic to 35.67.0.0/16, 37.61.0.0/16, or to 78.0.0.0/8.
After the fix, ISP3 will keep routing traffic to 35.67.0.0/16 (respecting the value val1 for attribute attr1) and to 78.0.0.0/8 through ISP2. It will not route traffic to 37.61.0.0/16.
But! All your other routes that you advertised earlier with perfectly fine attributes will continue working. This is what prevents this from becoming a DoS vulnerability.
Let's take a more complete example.
ISP1 advertises 2 routes to ISP2:
ISP2 doesn't know what attr1 is, and it advertisea the following routes to ISP3: The bug is that ISP3 will then stop routing any traffic to 35.67.0.0/16, 37.61.0.0/16, or to 78.0.0.0/8.After the fix, ISP3 will keep routing traffic to 35.67.0.0/16 (respecting the value val1 for attribute attr1) and to 78.0.0.0/8 through ISP2. It will not route traffic to 37.61.0.0/16.