CVE-2021-39155

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*
cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*
cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*

History

21 Feb 2024, 21:01

Type Values Removed Values Added
CWE CWE-863

31 Aug 2021, 19:35

Type Values Removed Values Added
References (CONFIRM) https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j - (CONFIRM) https://github.com/istio/istio/security/advisories/GHSA-7774-7vr3-cc8j - Third Party Advisory
References (MISC) https://datatracker.ietf.org/doc/html/rfc4343 - (MISC) https://datatracker.ietf.org/doc/html/rfc4343 - Third Party Advisory
CPE cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : 8.3
v2 : 5.0
v3 : 7.5

24 Aug 2021, 23:15

Type Values Removed Values Added
New CVE

Information

Published : 2021-08-24 23:15

Updated : 2024-02-21 21:01


NVD link : CVE-2021-39155

Mitre link : CVE-2021-39155

CVE.ORG link : CVE-2021-39155


JSON object : View

Products Affected

istio

  • istio
CWE
CWE-178

Improper Handling of Case Sensitivity

CWE-863

Incorrect Authorization