Описание
External Secrets Operator has DNS-based secret exfiltration via getHostByName in External Secrets v2 template engine
Summary
The v2 template engine in runtime/template/v2/template.go imports Sprig’s TxtFuncMap() and removes env and expandenv, but leaves getHostByName available to user-controlled templates. Because ESO executes templates inside the controller process, an attacker who can create or update templated ExternalSecret resources can trigger controller-side DNS lookups using secret-derived values, creating a DNS exfiltration primitive.
Impact
This is a confidentiality issue. In environments where untrusted or lower-trust users can author templated ExternalSecret resources and the controller can perform DNS resolution, fetched secret material can be exfiltrated through DNS without requiring direct outbound access from the attacker’s workload.
Ссылки
- https://github.com/external-secrets/external-secrets/security/advisories/GHSA-r2pg-r6h7-crf3
- https://nvd.nist.gov/vuln/detail/CVE-2026-34984
- https://github.com/external-secrets/external-secrets/commit/6800989bdc12782ca2605d3b8bf7f2876a16551a
- https://github.com/external-secrets/external-secrets/releases/tag/v2.3.0
Пакеты
github.com/external-secrets/external-secrets
< 1.3.3-0.20260331202714-6800989bdc12
1.3.3-0.20260331202714-6800989bdc12
github.com/external-secrets/external-secrets
>= 2.0.0, <= 2.2.0
Отсутствует
Связанные уязвимости
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 ...
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