Vulnerability-Lookup

FKIE_CVE-2021-35211

Vulnerability from fkie_nvd - Published: 2021-07-14 21:15 - Updated: 2026-06-17 03:57

Severity

9.0 (Critical) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
10.0 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Summary

Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability.

References

URL	Tags
psirt@solarwinds.com	https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit	Patch, Vendor Advisory
psirt@solarwinds.com	https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211	Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit	Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211	Patch, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211	US Government Resource

Impacted products

Vendor	Product	Version
solarwinds	serv-u	*
solarwinds	serv-u	15.2.3
solarwinds	serv-u	15.2.3

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "platforms": [
            "Windows"
          ],
          "product": "Serv-U Managed File Transfer Server and Serv-U Secured FTP",
          "vendor": "SolarWinds",
          "versions": [
            {
              "lessThan": "15.2.3 HF1",
              "status": "affected",
              "version": "SolarWinds Serv-U",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "psirt@solarwinds.com"
    }
  ],
  "cisaActionDue": "2021-11-17",
  "cisaExploitAdd": "2021-11-03",
  "cisaRequiredAction": "Apply updates per vendor instructions.",
  "cisaVulnerabilityName": "SolarWinds Serv-U Remote Code Execution Vulnerability",
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:solarwinds:serv-u:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "66A68531-7831-4875-B0AB-215C3E5A62B6",
              "versionEndExcluding": "15.2.3",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:solarwinds:serv-u:15.2.3:-:*:*:*:*:*:*",
              "matchCriteriaId": "9E8B32A1-90C1-4901-9B66-FA72E5787450",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:solarwinds:serv-u:15.2.3:hotfix1:*:*:*:*:*:*",
              "matchCriteriaId": "92569E9A-911C-4704-A962-047FF5E0E2CF",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Microsoft discovered a remote code execution (RCE) vulnerability in the SolarWinds Serv-U product utilizing a Remote Memory Escape Vulnerability. If exploited, a threat actor may be able to gain privileged access to the machine hosting Serv-U Only. SolarWinds Serv-U Managed File Transfer and Serv-U Secure FTP for Windows before 15.2.3 HF2 are affected by this vulnerability."
    },
    {
      "lang": "es",
      "value": "Microsoft descubri\u00f3 una vulnerabilidad de ejecuci\u00f3n de c\u00f3digo remota (RCE) en el producto SolarWinds Serv-U usando una Vulnerabilidad de Escape de Memoria Remota. Si es explotado, un actor de la amenaza puede ser capaz de obtener acceso privilegiado a la m\u00e1quina que aloja Serv-U solamente. SolarWinds Serv-U Managed File Transfer y Serv-U Secure FTP para Windows versiones anteriores a 15.2.3 HF2 est\u00e1n afectados por esta vulnerabilidad"
    }
  ],
  "id": "CVE-2021-35211",
  "lastModified": "2026-06-17T03:57:18.450",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "COMPLETE",
          "baseScore": 10.0,
          "confidentialityImpact": "COMPLETE",
          "integrityImpact": "COMPLETE",
          "vectorString": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 10.0,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 6.0,
        "source": "psirt@solarwinds.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.0,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-35211",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-02-04T19:06:30.616456Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2021-07-14T21:15:08.090",
  "references": [
    {
      "source": "psirt@solarwinds.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit"
    },
    {
      "source": "psirt@solarwinds.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211"
    }
  ],
  "sourceIdentifier": "psirt@solarwinds.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}

CVE-2021-35211 (GCVE-0-2021-35211)

Vulnerability from cvelistv5 – Published: 2021-07-14 20:55 – Updated: 2025-10-21 23:25

Title

Serv-U Remote Memory Escape Vulnerability

Summary

Severity

9 (Critical)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: active Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-02-04 19:06 UTC

CWE

Memory Escape Vulnerability in Solarwinds Serv-U
CWE-787 - Out-of-bounds Write

Assigner

SolarWinds mitre root Scorecard

References

3 references

URL	Tags
https://www.solarwinds.com/trust-center/security-…	x_refsource_MISC
https://www.microsoft.com/security/blog/2021/07/1…	x_refsource_MISC
https://www.cisa.gov/known-exploited-vulnerabilit…	government-resource

Impacted products

1 product

Vendor	Product	Version
SolarWinds	Serv-U Managed File Transfer Server and Serv-U Secured FTP	Affected: SolarWinds Serv-U , < 15.2.3 HF1 (custom)

Date Public

2021-07-13 00:00

Credits

SolarWinds would like to thank the Microsoft Threat Intelligence Center (MSTIC) and Microsoft Offensive Security Research teams for reporting on the issue in a responsible manner.

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T00:33:51.183Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.solarwinds.com/trust-center/security-advisories/cve-2021-35211"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.microsoft.com/security/blog/2021/07/13/microsoft-discovers-threat-actor-targeting-solarwinds-serv-u-software-with-0-day-exploit"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-35211",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-04T19:06:30.616456Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2021-11-03",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35211"
              },
              "type": "kev"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-787",
                "description": "CWE-787 Out-of-bounds Write",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-21T23:25:40.369Z",
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          "shortName": "CISA-ADP"
        },
        "references": [
          {
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              "government-resource"
            ],
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          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2021-11-03T00:00:00.000Z",
            "value": "CVE-2021-35211 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "platforms": [
            "Windows"
          ],
          "product": "Serv-U Managed File Transfer Server and Serv-U Secured FTP",
          "vendor": "SolarWinds",
          "versions": [
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              "status": "affected",
              "version": "SolarWinds Serv-U",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "SolarWinds would like to thank the Microsoft Threat Intelligence Center (MSTIC) and Microsoft Offensive Security Research teams for reporting on the issue in a responsible manner."
        }
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      "datePublic": "2021-07-13T00:00:00.000Z",
      "descriptions": [
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        }
      ],
      "metrics": [
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            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
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            "baseSeverity": "CRITICAL",
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            "scope": "CHANGED",
            "userInteraction": "NONE",
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      ],
      "problemTypes": [
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          "descriptions": [
            {
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              "type": "text"
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        "orgId": "49f11609-934d-4621-84e6-e02e032104d6",
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      "references": [
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          "DATE_PUBLIC": "2021-07-13T16:16:00.000Z",
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          "STATE": "PUBLIC",
          "TITLE": "Serv-U Remote Memory Escape Vulnerability"
        },
        "affects": {
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    "dateReserved": "2021-06-22T00:00:00.000Z",
    "dateUpdated": "2025-10-21T23:25:40.369Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

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FKIE_CVE-2021-35211

CVE-2021-35211 (GCVE-0-2021-35211)

Tags

Sightings

Nomenclature

Related by attack behaviour