Security advisory

{
  "id": "6f1c55cec0e5417fc7afe0d60f32c45720b68d996ad1f2a86604f61d730237f4",
  "url": "https://osv.dev/vulnerability/CVE-2018-1000520",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2018-1000520",
    "summary": "ARM mbedTLS version 2.7.0 and earlier contains a Ciphersuite Allows Incorrectly Signed Certificates vulnerability in mbedtls_ssl_get_verify_result() that can result in ECDSA-signed certificates are accepted, when only RSA-signed ones should be.. This attack appear to be exploitable via Peers negotiate a TLS-ECDH-RSA-* ciphersuite. Any of the peers can then provide an ECDSA-signed certificate, when only an RSA-signed one should be accepted..",
    "evidence": "osv:CVE-2018-1000520",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2018-1000520",
      "aliases": [
        "CVE-2018-1000520"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/Mbed-TLS/mbedtls",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "32605dc83042d737e715a685e53176388d73540e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.7.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "mbedtls-2.7.0",
            "mbedtls-2.7.0-rc1",
            "mbedtls-2.6.0",
            "mbedtls-2.6.0-rc1",
            "mbedtls-2.5.1",
            "mbedtls-2.5.0",
            "mbedtls-2.4.0",
            "mbedtls-2.2.1",
            "yotta-2.3.1",
            "mbedtls-2.3.0",
            "mbedtls-2.2.0",
            "mbedos-release-15-11",
            "mbedos-techcon-oob2",
            "mbedtls-2.1.2",
            "mbedtls-2.1.0",
            "mbedtls-2.1.1",
            "beta-oob-2",
            "mbedtls-2.0.0",
            "polarssl-1.3.9",
            "polarssl-1.3.8",
            "polarssl-1.3.7",
            "polarssl-1.3.6",
            "polarssl-1.3.5",
            "polarssl-1.3.4",
            "polarssl-1.3.3",
            "polarssl-1.3.2",
            "polarssl-1.3.1",
            "polarssl-1.3.0",
            "polarssl-1.3.0-rc0",
            "polarssl-1.2.6",
            "polarssl-1.2.5",
            "polarssl-1.2.4",
            "polarssl-1.2.2",
            "polarssl-1.2.1",
            "polarssl-1.2.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-1000520.json"
          }
        }
      ],
      "modified": "2026-10-20T10:49:39.239842154Z",
      "provider": "osv",
      "references": [
        "https://github.com/ARMmbed/mbedtls/issues/1561"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2018-1000520",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 380643,
  "published_at": "2018-06-26T16:29:01.353+00:00"
}