CVE-2026-34984

Описание

External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Versions 2.2.0 and below contain a vulnerability in runtime/template/v2/template.go where the v2 template engine removes env and expandenv from Sprig's TxtFuncMap() but leaves the getHostByName function accessible to user-controlled templates. Since ESO executes templates within the controller process, an attacker who can create or update templated ExternalSecret resources can invoke controller-side DNS lookups using secret-derived values. This creates a DNS exfiltration primitive, allowing fetched secret material to be leaked via DNS queries without requiring direct outbound network access from the attacker's workload. The impact is a confidentiality issue, particularly in environments where untrusted or lower-trust users can author templated ExternalSecret resources and the controller has DNS resolution capability. This issue has been fixed in version 2.3.0.

A flaw was found in External Secrets Operator. An attacker with the ability to create or update templated ExternalSecret resources can exploit a vulnerability in the v2 template engine. This flaw allows the attacker to use the getHostByName function to perform controller-side DNS lookups, leading to the exfiltration of sensitive secret material through DNS queries. This results in a confidentiality issue, as secret data can be leaked without requiring direct outbound network access from the attacker's workload.