GHSA-7774-7vr3-cc8j

Source

https://github.com/advisories/GHSA-7774-7vr3-cc8j

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/08/GHSA-7774-7vr3-cc8j/GHSA-7774-7vr3-cc8j.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-7774-7vr3-cc8j

Aliases

CVE-2021-39155

Related

Published

2021-08-30T16:15:56Z

Modified

2024-07-15T22:12:26.071844Z

Severity

8.3 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L CVSS Calculator

Summary

Authorization Policy Bypass Due to Case Insensitive Host Comparison

Details

Impact

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 Envoy 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

Istio 1.11.1 and above
Istio 1.10.4 and above
Istio 1.9.8 and above

Workarounds

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.

References

More details can be found in the Istio Security Bulletin.

For more information

If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com

Database specific

{
    "nvd_published_at": "2021-08-24T23:15:00Z",
    "cwe_ids": [
        "CWE-178"
    ],
    "severity": "HIGH",
    "github_reviewed": true,
    "github_reviewed_at": "2021-08-25T22:29:16Z"
}

References