CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:L/Au:N/C:N/I:P/A:N
EPSS
Percentile
58.8%
Security researcher Muneaki Nishimura reported that when certificate pinning is set to “strict” mode, a period (‘.’) appended to a hostname in the address of a site allowed the bypass key pinning (HPKP) and HTTP Strict Transport Security (HSTS). Sites with a period appended were treated as having a different origin than sites without the period. If an attacker had a security certificate for a domain with the added period, this would allow for a Man-in-the-middle (MITM) attack on users.