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Authorization bypass in Istio

Moderate severity GitHub Reviewed Published Feb 15, 2022 to the GitHub Advisory Database • Updated Oct 2, 2023

Package

gomod istio.io/istio (Go)

Affected versions

>= 1.5.0, < 1.5.9
>= 1.6.0, < 1.6.8

Patched versions

1.5.9
1.6.8

Description

In Istio 1.5.0 though 1.5.8 and Istio 1.6.0 through 1.6.7, when users specify an AuthorizationPolicy resource with DENY actions using wildcard suffixes (e.g. *-some-suffix) for source principals or namespace fields, callers will never be denied access, bypassing the intended policy.

Specific Go Packages Affected

istio.io/istio/pilot/pkg/security/authz/model/matcher

References

Reviewed May 12, 2021
Published to the GitHub Advisory Database Feb 15, 2022
Last updated Oct 2, 2023

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS score

0.079%
(35th percentile)

Weaknesses

CVE ID

CVE-2020-16844

GHSA ID

GHSA-82mm-ffjr-h86c

Source code

No known source code
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