// For flags

CVE-2021-31921

istio/istio: authorization bypass when using AUTO_PASSTHROUGH

Severity Score

9.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Istio before 1.8.6 and 1.9.x before 1.9.5 contains a remotely exploitable vulnerability where an external client can access unexpected services in the cluster, bypassing authorization checks, when a gateway is configured with AUTO_PASSTHROUGH routing configuration.

Istio antes de la versión 1.8.6 y 1.9.x antes de la versión 1.9.5 contiene una vulnerabilidad explotable de forma remota por la que un cliente externo puede acceder a servicios inesperados en el clúster, saltándose las comprobaciones de autorización, cuando una puerta de enlace está configurada con la configuración de enrutamiento AUTO_PASSTHROUGH

An authorization bypass vulnerability was found in istio. When the istio gateway is configured with TLS mode `AUTO_PASSTHROUGH`, it is possible for a malicious user to bypass the authorization checks and gain access to protected services. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-04-30 CVE Reserved
  • 2021-05-20 CVE Published
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • 2024-10-05 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-862: Missing Authorization
  • CWE-863: Incorrect Authorization
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Istio
Search vendor "Istio"
 Istio
Search vendor "Istio" for product "Istio"
 < 1.8.6
Search vendor "Istio" for product "Istio" and version " < 1.8.6"
-
Affected
Istio
Search vendor "Istio"
 Istio
Search vendor "Istio" for product "Istio"
 >= 1.9.0 < 1.9.5
Search vendor "Istio" for product "Istio" and version " >= 1.9.0 < 1.9.5"
-
Affected