Vulnerability-Lookup

GHSA-6M36-86VP-X4XX

Vulnerability from github – Published: 2022-05-24 17:31 – Updated: 2026-08-11 21:31

Details

A vulnerability in the TCP Intercept functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Access Control Policies (including Geolocation) and Service Polices on an affected system. The vulnerability exists because TCP Intercept is invoked when the embryonic connection limit is reached, which can cause the underlying detection engine to process the packet incorrectly. An attacker could exploit this vulnerability by sending a crafted stream of traffic that matches a policy on which TCP Intercept is configured. A successful exploit could allow the attacker to match on an incorrect policy, which could allow the traffic to be forwarded when it should be dropped. In addition, the traffic could incorrectly be dropped.

Severity

5.8 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2020-3565"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284",
      "CWE-287"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-10-21T19:15:00Z",
    "severity": "MODERATE"
  },
  "details": "A vulnerability in the TCP Intercept functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Access Control Policies (including Geolocation) and Service Polices on an affected system. The vulnerability exists because TCP Intercept is invoked when the embryonic connection limit is reached, which can cause the underlying detection engine to process the packet incorrectly. An attacker could exploit this vulnerability by sending a crafted stream of traffic that matches a policy on which TCP Intercept is configured. A successful exploit could allow the attacker to match on an incorrect policy, which could allow the traffic to be forwarded when it should be dropped. In addition, the traffic could incorrectly be dropped.",
  "id": "GHSA-6m36-86vp-x4xx",
  "modified": "2026-08-11T21:31:42Z",
  "published": "2022-05-24T17:31:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-3565"
    },
    {
      "type": "WEB",
      "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcp-intercept-bypass-xG9M3PbY"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2020-3565 (GCVE-0-2020-3565)

Vulnerability from cvelistv5 – Published: 2020-10-21 18:40 – Updated: 2024-11-13 17:46

Title

Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability

Summary

Severity

5.8 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-11-13 17:12 UTC

CWE

CWE-284

Assigner

cisco CNA under the mitre root

CNA scorecard C 66/100 over 434 records in the last 180 days details

References

1 reference

URL	Tags
https://tools.cisco.com/security/center/content/C…	vendor-advisoryx_refsource_CISCO

Impacted products

1 product

Vendor	Product	Version
Cisco	Cisco Firepower Threat Defense Software	Affected: n/a

Date Public

2020-10-21 00:00

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T07:37:55.034Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "20201021 Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability",
            "tags": [
              "vendor-advisory",
              "x_refsource_CISCO",
              "x_transferred"
            ],
            "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcp-intercept-bypass-xG9M3PbY"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2020-3565",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-11-13T17:12:14.999470Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-11-13T17:46:42.462Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Cisco Firepower Threat Defense Software",
          "vendor": "Cisco",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
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        }
      ],
      "datePublic": "2020-10-21T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
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        }
      ],
      "exploits": [
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          "value": "The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory."
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      "metrics": [
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          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
            "version": "3.1"
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      "problemTypes": [
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          "descriptions": [
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      "providerMetadata": {
        "dateUpdated": "2020-10-21T18:40:53.000Z",
        "orgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
        "shortName": "cisco"
      },
      "references": [
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        }
      ],
      "source": {
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          ]
        ],
        "discovery": "INTERNAL"
      },
      "title": "Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability",
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "psirt@cisco.com",
          "DATE_PUBLIC": "2020-10-21T16:00:00",
          "ID": "CVE-2020-3565",
          "STATE": "PUBLIC",
          "TITLE": "Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "Cisco Firepower Threat Defense Software",
                      "version": {
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            }
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        "exploit": [
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        "impact": {
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            {
              "name": "20201021 Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability",
              "refsource": "CISCO",
              "url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcp-intercept-bypass-xG9M3PbY"
            }
          ]
        },
        "source": {
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          "defect": [
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    "state": "PUBLISHED"
  },
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}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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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