Security advisory

{
  "id": "2c9525c7b5cd0145b179c3b4696f3e153d1c22e1c56efe196f86cbe6644e63b7",
  "url": "https://osv.dev/vulnerability/CVE-2021-27217",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-27217",
    "summary": "An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.",
    "evidence": "osv:CVE-2021-27217",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-27217",
      "aliases": [
        "CVE-2021-27217"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/yubico/yubihsm-shell",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "a2d66a90426dddac0d2060d2b4fce5c7545a6bc8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:yubico:yubihsm-shell:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.0.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.0.3",
            "2.0.2",
            "2.0.1",
            "2.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-27217.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:35.108762930Z",
      "provider": "osv",
      "references": [
        "https://github.com/Yubico/yubihsm-shell/releases",
        "https://www.yubico.com/support/security-advisories/ysa-2021-01/",
        "https://blog.inhq.net/posts/yubico-libyubihsm-vuln2"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-27217",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385660,
  "published_at": "2021-03-04T18:15:14.05+00:00"
}