FKIE_CVE-2026-59341

Vulnerability from fkie_nvd - Published: 2026-09-15 10:17 - Updated: 2026-09-18 19:21
Severity
4.2 (Medium) - CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N
Summary
A security vulnerability exists in the Sealed Secrets controller's unauthenticated POST endpoints. By submitting a modified payload containing custom Go template logic in spec.template.data, an attacker with internal network access can abuse the handler as a decryption oracle to recover the full plaintext of any sealed secret. The POST /v1/verify and /v1/rotate handlers call Unseal() to decrypt target secrets, then render any Go templates found in spec.template.data.* using the decrypted payload as the evaluation context (pkg/apis/sealedsecrets/v1alpha1/sealedsecret_expansion.go). Errors encountered during template execution are directly reflected in the resulting HTTP response status codes. Missing AEAD label binding: the spec.template.data field is omitted from the AEAD authenticated-data label binding ciphertext to metadata. As a result, an attacker can copy a target's valid metadata and encryptedData verbatim, satisfying AEAD decryption and label validation, while freely replacing spec.template.data with arbitrary template logic. Side-channel oracle: template execution errors map directly to HTTP response codes. HTTP 200 (OK) indicates template execution succeeded; HTTP 409 (Conflict) indicates template execution failed (e.g. via {{ fail "..." }}). By injecting conditional statements such as {{ if eq (substr 0 1 .password) "S" }}ok{{ else }}{{ fail "x" }}{{ end }}, an attacker receives an HTTP 200 status when a character guess is correct and an HTTP 409 when it is incorrect. This differential response leaks one character-equality bit per request, allowing full secret extraction over successive queries. Attack vector & prerequisites: unauthenticated; requires network access to the controller's internal service port (:8080). Although this service is not exposed to the public internet by default, it is accessible to any pod within the Kubernetes cluster or via a kubectl port-forward connection.
References
security@vmware.comhttps://github.com/bitnami/sealed-secrets
security@vmware.comhttps://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "sealed-secrets",
          "repo": "https://github.com/bitnami/sealed-secrets",
          "vendor": "Bitnami",
          "versions": [
            {
              "lessThanOrEqual": "0.38.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.40.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@vmware.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A security vulnerability exists in the Sealed Secrets controller\u0027s unauthenticated POST endpoints. By submitting a modified payload containing custom Go template logic in spec.template.data, an attacker with internal network access can abuse the handler as a decryption oracle to recover the full plaintext of any sealed secret.\n\n\n\nThe POST /v1/verify and /v1/rotate handlers call Unseal() to decrypt target secrets, then render any Go templates found in spec.template.data.* using the decrypted payload as the evaluation context (pkg/apis/sealedsecrets/v1alpha1/sealedsecret_expansion.go). Errors encountered during template execution are directly reflected in the resulting HTTP response status codes.\n\n\n\nMissing AEAD label binding: the spec.template.data field is omitted from the AEAD authenticated-data label binding ciphertext to metadata. As a result, an attacker can copy a target\u0027s valid metadata and encryptedData verbatim, satisfying AEAD decryption and label validation, while freely replacing spec.template.data with arbitrary template logic.\n\n\n\nSide-channel oracle: template execution errors map directly to HTTP response codes. HTTP 200 (OK) indicates template execution succeeded; HTTP 409 (Conflict) indicates template execution failed (e.g. via {{ fail \"...\" }}).\n\n\n\nBy injecting conditional statements such as {{ if eq (substr 0 1 .password) \"S\" }}ok{{ else }}{{ fail \"x\" }}{{ end }}, an attacker receives an HTTP 200 status when a character guess is correct and an HTTP 409 when it is incorrect. This differential response leaks one character-equality bit per request, allowing full secret extraction over successive queries.\n\n\n\nAttack vector \u0026 prerequisites: unauthenticated; requires network access to the controller\u0027s internal service port (:8080). Although this service is not exposed to the public internet by default, it is accessible to any pod within the Kubernetes cluster or via a kubectl port-forward connection."
    }
  ],
  "id": "CVE-2026-59341",
  "lastModified": "2026-09-18T19:21:34.307",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.2,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 0.5,
        "impactScore": 3.6,
        "source": "security@vmware.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-59341",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-15T17:27:25.731287Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-15T10:17:05.673",
  "references": [
    {
      "source": "security@vmware.com",
      "url": "https://github.com/bitnami/sealed-secrets"
    },
    {
      "source": "security@vmware.com",
      "url": "https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/bitnami/sealed-secrets/security/advisories/GHSA-qj4p-m373-p2wg"
    }
  ],
  "sourceIdentifier": "security@vmware.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-203"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}



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