Fragments in Path May Lead to Authorization Policy Bypass
CVE-2021-39156

8.1HIGH

Key Information:

Vendor

Istio

Status
Istio
Vendor
CVE Published:
24 August 2021

What is CVE-2021-39156?

Istio is an open source platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with #fragment in the path may bypass Istio’s URI path based authorization policies. Patches are available in Istio 1.11.1, Istio 1.10.4 and Istio 1.9.8. As a work around a Lua filter may be written to normalize the path.

Affected Version(s)

istio < 1.9.8 < 1.9.8

istio >= 1.10.0, < 1.10.4 < 1.10.0, 1.10.4

istio >= 1.11.0, < 1.11.1 < 1.11.0, 1.11.1

References

https://github.com/istio/istio/security/advisories/GHSA-h...
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https://istio.io/latest/news/security/istio-security-2021...
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CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.