CVE-2021-39155

2021-08-2422:15:06

redhat.com

access.redhat.com

authorization bypass

istio

confidentiality

integrity

system availability

host comparison

CVSS2

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS3

8.3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

LOW

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

EPSS

0.001

Percentile

49.8%

JSON

An authorization bypass vulnerability was found in istio/istio. The case insensitive host comparison incorrectly works when evaluating rules specified with host or notHost. This flaw allows an attacker to bypass an Istio authorization policy that uses hosts in the rules, potentially gaining access to the downstream services. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.