Improper Handling of Case Sensitivity Affecting istio-pilot-discovery-1.21 package, versions <1.21.3-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.14% (52nd percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-ISTIOPILOTDISCOVERY121-6809149
  • published17 Jun 2024
  • disclosed24 Aug 2021

Introduced: 24 Aug 2021

CVE-2021-39155  (opens in a new tab)
CWE-178  (opens in a new tab)
CWE-863  (opens in a new tab)

How to fix?

Upgrade Chainguard istio-pilot-discovery-1.21 to version 1.21.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream istio-pilot-discovery-1.21 package and not the istio-pilot-discovery-1.21 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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, 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 guide.

CVSS Scores

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