CVE-2021-39155

Improper Handling of Case Sensitivity in go/github.com/istio/istio

Identifier

CVE-2021-39155

Package Slug

go/github.com/istio/istio

Vulnerability

Improper Handling of Case Sensitivity

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 , 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, Istio and Istio 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 guide.

Affected Versions

All versions before 1.9.8, all versions starting from 1.10.0 before 1.10.4, all versions starting from 1.11.0 before 1.11.1

Solution

Upgrade to version 1.9.8, 1.10.4, 1.11.1 or above.

Last Modified

2021-09-02

source