8.2 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
0.001 Low
EPSS
Percentile
20.9%
A flaw was found in Envoy that allows for mixed-case schemes in HTTP/2. However, some internal scheme checks in Envoy are case-sensitive, leading to incorrect handling of requests and responses with mixed case schemes. For example, if a request with a mixed scheme HTTP is sent to the OAuth2 filter, it will fail the exact-match checks for HTTP and inform the remote endpoint the scheme is HTTP, thus potentially bypassing OAuth2 checks specific to HTTP requests.