Vulnerability-Lookup

FKIE_CVE-2021-23758

Vulnerability from fkie_nvd - Published: 2021-12-03 20:15 - Updated: 2026-08-27 04:16

Severity

8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

All versions of package ajaxpro.2 are vulnerable to Deserialization of Untrusted Data due to the possibility of deserialization of arbitrary .NET classes, which can be abused to gain remote code execution.

References

URL	Tags
report@snyk.io	http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html	Exploit, VDB Entry
report@snyk.io	https://github.com/michaelschwarz/Ajax.NET-Professional/commit/b0e63be5f0bb20dfce507cb8a1a9568f6e73de57	Patch, Third Party Advisory
report@snyk.io	https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html	Exploit, VDB Entry
af854a3a-2127-422b-91ae-364da2661108	https://github.com/michaelschwarz/Ajax.NET-Professional/commit/b0e63be5f0bb20dfce507cb8a1a9568f6e73de57	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971	Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://blog.talosintelligence.com/uat-10147-chinese-speaking-adversary-integrates-agentic-ai-into-post-compromise-operations/	Exploit, Third Party Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-23758	US Government Resource

Impacted products

	Vendor	Product	Version
	ajaxpro.2_project	ajaxpro.2	*
	michaelschwarz	ajax.net_professional	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "AjaxPro.2",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "unspecified",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "report@snyk.io"
    }
  ],
  "cisaActionDue": "2026-09-09",
  "cisaExploitAdd": "2026-08-26",
  "cisaRequiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA\u2019s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA\u2019s \u201cForensics Triage Requirements\u201d (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset\u0027s internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
  "cisaVulnerabilityName": "Ajax.NET Professional Deserialization of Untrusted Data Vulnerability",
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:ajaxpro.2_project:ajaxpro.2:*:*:*:*:*:.net:*:*",
              "matchCriteriaId": "0C5825C3-B14F-47EB-9FD9-324A314A5177",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:michaelschwarz:ajax.net_professional:*:*:*:*:*:.net:*:*",
              "matchCriteriaId": "3F7FC210-4C84-424D-AE68-BC3DB95F88AA",
              "versionEndExcluding": "21.10.30.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "All versions of package ajaxpro.2 are vulnerable to Deserialization of Untrusted Data due to the possibility of deserialization of arbitrary .NET classes, which can be abused to gain remote code execution."
    },
    {
      "lang": "es",
      "value": "Todas las versiones del paquete ajaxpro.2 son vulnerables a una Deserializaci\u00f3n de Datos No Confiables debido a la posibilidad de deserializaci\u00f3n de clases .NET arbitrarias, que pueden ser abusadas para obtener la ejecuci\u00f3n de c\u00f3digo remota"
    }
  ],
  "id": "CVE-2021-23758",
  "lastModified": "2026-08-27T04:16:38.863",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 7.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "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": 8.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 5.9,
        "source": "report@snyk.io",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-23758",
          "options": [
            {
              "exploitation": "active"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-26T00:00:00+00:00",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2021-12-03T20:15:07.557",
  "references": [
    {
      "source": "report@snyk.io",
      "tags": [
        "Exploit",
        "VDB Entry"
      ],
      "url": "http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html"
    },
    {
      "source": "report@snyk.io",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/michaelschwarz/Ajax.NET-Professional/commit/b0e63be5f0bb20dfce507cb8a1a9568f6e73de57"
    },
    {
      "source": "report@snyk.io",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "VDB Entry"
      ],
      "url": "http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/michaelschwarz/Ajax.NET-Professional/commit/b0e63be5f0bb20dfce507cb8a1a9568f6e73de57"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ],
      "url": "https://blog.talosintelligence.com/uat-10147-chinese-speaking-adversary-integrates-agentic-ai-into-post-compromise-operations/"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "US Government Resource"
      ],
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-23758"
    }
  ],
  "sourceIdentifier": "report@snyk.io",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}

CVE-2021-23758 (GCVE-0-2021-23758)

Vulnerability from cvelistv5 – Published: 2021-12-03 20:05 – Updated: 2026-08-27 03:56

Title

Deserialization of Untrusted Data

Summary

Severity

8.1 (High)


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

SSVC

Exploitation: active Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-26 00:00 UTC

CWE

Deserialization of Untrusted Data
CWE-502 - Deserialization of Untrusted Data

Assigner

snyk mitre root

References

5 references

URL	Tags
https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971
https://github.com/michaelschwarz/Ajax.NET-Profes…
http://packetstormsecurity.com/files/175677/AjaxP…
https://blog.talosintelligence.com/uat-10147-chin…	third-party-advisory
https://www.cisa.gov/known-exploited-vulnerabilit…	government-resource

Impacted products

1 product

Vendor	Product	Version
n/a	AjaxPro.2	Affected: 0 , < unspecified (custom)

Date Public

2021-12-03 00:00

Credits

Hans-Martin Münch (MOGWAI LABS)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T19:14:09.129Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/michaelschwarz/Ajax.NET-Professional/commit/b0e63be5f0bb20dfce507cb8a1a9568f6e73de57"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-23758",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-26T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2026-08-26",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-23758"
              },
              "type": "kev"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-502",
                "description": "CWE-502 Deserialization of Untrusted Data",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-27T03:56:43.403Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "third-party-advisory"
            ],
            "url": "https://blog.talosintelligence.com/uat-10147-chinese-speaking-adversary-integrates-agentic-ai-into-post-compromise-operations/"
          },
          {
            "tags": [
              "government-resource"
            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-23758"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2026-08-26T00:00:00.000Z",
            "value": "CVE-2021-23758 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "AjaxPro.2",
          "vendor": "n/a",
          "versions": [
            {
              "lessThan": "unspecified",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Hans-Martin M\u00fcnch (MOGWAI LABS)"
        }
      ],
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      "descriptions": [
        {
          "lang": "en",
          "value": "All versions of package ajaxpro.2 are vulnerable to Deserialization of Untrusted Data due to the possibility of deserialization of arbitrary .NET classes, which can be abused to gain remote code execution."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Deserialization of Untrusted Data",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-11-14T03:06:35.776Z",
        "orgId": "bae035ff-b466-4ff4-94d0-fc9efd9e1730",
        "shortName": "snyk"
      },
      "references": [
        {
          "url": "https://snyk.io/vuln/SNYK-DOTNET-AJAXPRO2-1925971"
        },
        {
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        },
        {
          "url": "http://packetstormsecurity.com/files/175677/AjaxPro-Deserialization-Remote-Code-Execution.html"
        }
      ],
      "title": "Deserialization of Untrusted Data"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "bae035ff-b466-4ff4-94d0-fc9efd9e1730",
    "assignerShortName": "snyk",
    "cveId": "CVE-2021-23758",
    "datePublished": "2021-12-03T20:05:12.932Z",
    "dateReserved": "2021-01-08T00:00:00.000Z",
    "dateUpdated": "2026-08-27T03:56:43.403Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.

Action not permitted

FKIE_CVE-2021-23758

CVE-2021-23758 (GCVE-0-2021-23758)

Tags

Sightings

Nomenclature