FKIE_CVE-2026-33662

Vulnerability from fkie_nvd - Published: 2026-04-24 19:17 - Updated: 2026-06-05 20:21
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, "PS size", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration.
References
security-advisories@github.comhttps://github.com/OP-TEE/optee_os/security/advisories/GHSA-4cf8-v5g3-73grPatch, Vendor Advisory
Impacted products
Vendor Product Version
trustedfirmware op-tee *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:trustedfirmware:op-tee:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "BF89E0A3-1EAB-4954-8F4C-3AA14C015E5E",
              "versionEndIncluding": "4.10.0",
              "versionStartIncluding": "3.8.0",
              "vulnerable": true
            }
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          "negate": false,
          "operator": "OR"
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "OP-TEE is a Trusted Execution Environment (TEE) designed as companion to a non-secure Linux kernel running on Arm; Cortex-A cores using the TrustZone technology. From 3.8.0 to 4.10, in the function emsa_pkcs1_v1_5_encode() in core/drivers/crypto/crypto_api/acipher/rsassa.c, the amount of padding needed, \"PS size\", is calculated by subtracting the size of the digest and other fields required for the EMA-PKCS1-v1_5 encoding from the size of the modulus of the key. By selecting a small enough modulus, this subtraction can overflow. The padding is added as a string of 0xFF bytes with a call to memset(), and an underflowed integer will cause the memset() call to overwrite until OP-TEE crashes. This only affects platforms registering RSA acceleration."
    }
  ],
  "id": "CVE-2026-33662",
  "lastModified": "2026-06-05T20:21:14.723",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
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  "published": "2026-04-24T19:17:09.997",
  "references": [
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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          "value": "CWE-190"
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      "source": "security-advisories@github.com",
      "type": "Primary"
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