SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-39156

Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies.

HIGH 7.5EPSS 1.18%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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. Istio 1.11.0, 1.10.3 and below, and 1.9.7 and below contain a remotely exploitable vulnerability where an HTTP request with `#fragment` in the path may bypass Istio’s URI path based authorization policies. 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 the path.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.18% probability · 66th percentile
CISA KEV
Not listed
Weakness
CWE-863, CWE-706
Affected
istio/istio
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.