Skip to content

Istio Authorization Bypass Vulnerability

Moderate severity GitHub Reviewed Published May 24, 2022 to the GitHub Advisory Database • Updated Aug 7, 2023
Withdrawn This advisory was withdrawn on Aug 7, 2023

Package

gomod istio.io/istio (Go)

Affected versions

< 1.8.6
>= 1.9.0, <= 1.9.4

Patched versions

1.8.6
1.9.5

Description

Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.

References

Published by the National Vulnerability Database May 27, 2021
Published to the GitHub Advisory Database May 24, 2022
Reviewed Jul 11, 2023
Last updated Aug 7, 2023
Withdrawn Aug 7, 2023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
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
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:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS score

0.079%
(36th percentile)

Weaknesses

CVE ID

CVE-2021-31920

GHSA ID

GHSA-6q5m-22mq-q2xv

Source code

No known source code
Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.