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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2021-39155 Detail

Description

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. According to [RFC 4343](https://datatracker.ietf.org/doc/html/rfc4343), Istio authorization policy should compare the hostname in the HTTP Host header in a case insensitive way, but currently the comparison is case sensitive. The proxy will route the request hostname in a case-insensitive way which means the authorization policy could be bypassed. As an example, the user may have an authorization policy that rejects request with hostname "httpbin.foo" for some source IPs, but the attacker can bypass this by sending the request with hostname "Httpbin.Foo". 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 Host header before the authorization check. This is similar to the Path normalization presented in the [Security Best Practices](https://istio.io/latest/docs/ops/best-practices/security/#case-normalization) guide.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://datatracker.ietf.org/doc/html/rfc4343 Third Party Advisory 
https://datatracker.ietf.org/doc/html/rfc4343 Third Party Advisory 
https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j Third Party Advisory 
https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-863 Incorrect Authorization cwe source acceptance level NIST  
CWE-178 Improper Handling of Case Sensitivity cwe source acceptance level NIST   GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-39155
NVD Published Date:
08/24/2021
NVD Last Modified:
11/21/2024
Source:
GitHub, Inc.