GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

FKIE_CVE-2021-26095

Vulnerability from fkie_nvd - Published: 2021-07-20 11:15 - Updated: 2026-06-17 03:42
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
The combination of various cryptographic issues in the session management of FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6, including the encryption construction of the session cookie, may allow a remote attacker already in possession of a cookie to possibly reveal and alter or forge its content, thereby escalating privileges.
References
psirt@fortinet.comhttps://fortiguard.com/advisory/FG-IR-21-019Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://fortiguard.com/advisory/FG-IR-21-019Vendor Advisory
Impacted products
Vendor Product Version
fortinet fortimail *
fortinet fortimail *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Fortinet FortiMail",
          "vendor": "Fortinet",
          "versions": [
            {
              "status": "affected",
              "version": "FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6"
            }
          ]
        }
      ],
      "source": "psirt@fortinet.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0EEAD569-3345-4618-A239-EEDC352C4156",
              "versionEndIncluding": "6.2.6",
              "versionStartIncluding": "6.2.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5DAB4EFB-D73F-4FC5-8FE7-278BADB9F78E",
              "versionEndExcluding": "6.4.5",
              "versionStartIncluding": "6.4.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The combination of various cryptographic issues in the session management of FortiMail 6.4.0 through 6.4.4 and 6.2.0 through 6.2.6, including the encryption construction of the session cookie, may allow a remote attacker already in possession of a cookie to possibly reveal and alter or forge its content, thereby escalating privileges."
    },
    {
      "lang": "es",
      "value": "Una combinaci\u00f3n de varios problemas criptogr\u00e1ficos en la administraci\u00f3n de sesiones de FortiMail versiones 6.4.0 hasta 6.4.4 y versiones 6.2.0 hasta 6.2.6, incluy\u00e9ndo la construcci\u00f3n del cifrado de la cookie de sesi\u00f3n, puede permitir a un atacante remoto que ya est\u00e9 en posesi\u00f3n de una cookie, a posiblemente revelar y alterar o falsificar su contenido, escalando as\u00ed los privilegios"
    }
  ],
  "id": "CVE-2021-26095",
  "lastModified": "2026-06-17T03:42:51.133",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "SINGLE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 6.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:S/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 8.0,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.9,
        "source": "psirt@fortinet.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-26095",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-10-23T14:13:34.648152Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2021-07-20T11:15:11.477",
  "references": [
    {
      "source": "psirt@fortinet.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://fortiguard.com/advisory/FG-IR-21-019"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://fortiguard.com/advisory/FG-IR-21-019"
    }
  ],
  "sourceIdentifier": "psirt@fortinet.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.