The german wikipedia article to BGP states (translated):
In the basic configuration, a BGP-Router is susceptible to spoofig attacks, through which the attacker can manipulate the routers. By using an authentiation between the BGP peers with a individual password (based on MD5 hashes), the data exchange between BGP routers can be secured. This makes it harder to use spoofic attacs, but it is especially dependent on the security of MD5, which is not seen as secure by crypto experts anymore. (https://de.wikipedia.org/wiki/Border_Gateway_Protocol)
How exactly is the security dependent on the security of MD5? Like the password/pre-shared key would need to be stored on both routers (one sends it - the other verifys it). So if the hash is actually stolen, it could be used without any need for decryption, or am I wrong with that? So how would anyone benefit from using a stronger hashing algorithm (or especially how does the security flaws of MD5 make the pre-shared key less secure)?