csirt@kutim:~/threat-intel/cve/CVE-2021-39155

Katalog CVE

CVSS 7.5 · High EPSS 1,2%

Kerentanan Improper Handling of Case Sensitivity pada istio. Skor CVSS 3.1 7.5 (High) menurut NVD.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD
24 Agustus 2021
Terakhir diubah
17 Juni 2026
Status NVD
Modified
CVSS 3.1
7.5 (High), sumber NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-178: Improper Handling of Case Sensitivity
CWE-863: Incorrect Authorization
EPSS (30 hari)
1,2% peluang dieksploitasi; lebih tinggi dari 67,0% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
istio istio Semua versi sebelum 1.9.8
istio istio Versi 1.10.0 hingga sebelum 1.10.4
istio istio Versi 1.11.0 hingga sebelum 1.11.1

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:10 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.