3 ms·
Not sure if that's what GP is referring to, but one thing it would do is increase your attack surface... If I setup bank.mycompany.com and discourse.mycompany.
by unilynx 7y ago
Not sure if that's what GP is referring to, but one thing it would do is increase your attack surface...
If I setup bank.mycompany.com and discourse.mycompany.com as CNAMEs, bank.mycompany.com now sets a cookie at mycompany.com, and discourse.mycompany.com is hacked.. the latter could be used to read the cookies from the first. Which wouldn't have happened without the CNAMEs, or if my company.com was on the PSL.
Lots of "ifs" and "buts" though before something like that would happen in practice...
- zenexer 7y agoThat has no relation to the use of CNAMEs—this problem exists even if CNAME records aren’t used. If “z” is a public suffix, x.y.z can set and read cookies from x.y.z and y.z, but not z. Whether this is possible has nothing to do with whether x.y.z is a CNAME.