CVE-2021-43797 (GCVE-0-2021-43797)

Vulnerability from cvelistv5 – Published: 2021-12-09 00:00 – Updated: 2024-08-04 04:03
VLAI
Title
HTTP fails to validate against control chars in header names which may lead to HTTP request smuggling
Summary
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Netty prior to version 4.1.71.Final skips control chars when they are present at the beginning / end of the header name. It should instead fail fast as these are not allowed by the spec and could lead to HTTP request smuggling. Failing to do the validation might cause netty to "sanitize" header names before it forward these to another remote system when used as proxy. This remote system can't see the invalid usage anymore, and therefore does not do the validation itself. Users should upgrade to version 4.1.71.Final.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CWE
  • CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')
Assigner
References
Impacted products
Vendor Product Version CPE status
netty netty Affected: <= 4.1.7.0.Final
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T04:03:08.898Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20220107-0003/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
          },
          {
            "name": "[debian-lts-announce] 20230111 [SECURITY] [DLA 3268-1] netty security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html"
          },
          {
            "name": "DSA-5316",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2023/dsa-5316"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "netty",
          "vendor": "netty",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 4.1.7.0.Final"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers \u0026 clients. Netty prior to version 4.1.71.Final skips control chars when they are present at the beginning / end of the header name. It should instead fail fast as these are not allowed by the spec and could lead to HTTP request smuggling. Failing to do the validation might cause netty to \"sanitize\" header names before it forward these to another remote system when used as proxy. This remote system can\u0027t see the invalid usage anymore, and therefore does not do the validation itself. Users should upgrade to version 4.1.71.Final."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-01-12T00:00:00.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "url": "https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq"
        },
        {
          "url": "https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
        },
        {
          "url": "https://security.netapp.com/advisory/ntap-20220107-0003/"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
        },
        {
          "name": "[debian-lts-announce] 20230111 [SECURITY] [DLA 3268-1] netty security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html"
        },
        {
          "name": "DSA-5316",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.debian.org/security/2023/dsa-5316"
        }
      ],
      "source": {
        "advisory": "GHSA-wx5j-54mm-rqqq",
        "discovery": "UNKNOWN"
      },
      "title": "HTTP fails to validate against control chars in header names which may lead to HTTP request smuggling"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-43797",
    "datePublished": "2021-12-09T00:00:00.000Z",
    "dateReserved": "2021-11-16T00:00:00.000Z",
    "dateUpdated": "2024-08-04T04:03:08.898Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-43797",
      "date": "2026-09-21",
      "epss": "0.02682",
      "percentile": "0.85108"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "netty",
                "vendor": "netty",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c= 4.1.7.0.Final"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "F63C0F0C-1D4C-4383-820A-9325DE306780",
                    "versionEndExcluding": "4.1.71",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:quarkus:quarkus:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "9050DC4B-0A83-436F-9AE5-6DC28EC7F69D",
                    "versionEndExcluding": "2.5.3",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*",
                    "matchCriteriaId": "5735E553-9731-4AAC-BCFF-989377F817B3",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*",
                    "matchCriteriaId": "BDFB1169-41A0-4A86-8E4F-FDA9730B1E94",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:oracle:banking_deposits_and_lines_of_credit_servicing:2.7:*:*:*:*:*:*:*",
                    "matchCriteriaId": "ED63D221-31FA-480F-802F-844334F429F5",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:banking_party_management:2.7.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "C542DC5E-6657-4178-9C69-46FD3C187D56",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:banking_platform:2.6.2:*:*:*:*:*:*:*",
                    "matchCriteriaId": "132CE62A-FBFC-4001-81EC-35D81F73AF48",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:coherence:12.2.1.4.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "2FF57C7A-92C9-4D71-A7B1-CC9DEFAA8193",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:coherence:14.1.1.0.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "5FA64A1D-34F9-4441-857A-25C165E6DBB6",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_cloud_native_core_binding_support_function:1.11.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "10323322-F6C0-4EA7-9344-736F7A80AA5F",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_cloud_native_core_network_slice_selection_function:1.8.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "3AA09838-BF13-46AC-BB97-A69F48B73A8A",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.15.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "B4367D9B-BF81-47AD-A840-AC46317C774D",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_cloud_native_core_security_edge_protection_proxy:1.7.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "BD4349FE-EEF8-489A-8ABF-5FCD55EC6DE0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_cloud_native_core_unified_data_repository:1.15.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "C6EAA723-2A23-4151-930B-86ACF9CC1C0C",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_design_studio:7.4.2:*:*:*:*:*:*:*",
                    "matchCriteriaId": "A67AA54B-258D-4D09-9ACB-4085E0B3E585",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:communications_instant_messaging_server:8.1:*:*:*:*:*:*:*",
                    "matchCriteriaId": "47CE14F1-7E98-4C3B-A817-C54273F23464",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:helidon:1.4.10:*:*:*:*:*:*:*",
                    "matchCriteriaId": "4E7626D2-D9FF-416A-9581-852CED0D8C24",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:helidon:2.4.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "99344A5D-F4B7-49B4-9AE6-0E2FB3874EA5",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.58:*:*:*:*:*:*:*",
                    "matchCriteriaId": "D9DB4A14-2EF5-4B54-95D2-75E6CF9AA0A9",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.59:*:*:*:*:*:*:*",
                    "matchCriteriaId": "C8AF00C6-B97F-414D-A8DF-057E6BFD8597",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers \u0026 clients. Netty prior to version 4.1.71.Final skips control chars when they are present at the beginning / end of the header name. It should instead fail fast as these are not allowed by the spec and could lead to HTTP request smuggling. Failing to do the validation might cause netty to \"sanitize\" header names before it forward these to another remote system when used as proxy. This remote system can\u0027t see the invalid usage anymore, and therefore does not do the validation itself. Users should upgrade to version 4.1.71.Final."
          },
          {
            "lang": "es",
            "value": "Netty es un marco de trabajo de aplicaciones de red as\u00edncronas impulsadas por eventos para el desarrollo r\u00e1pido de servidores y clientes de protocolo de alto rendimiento mantenibles. Netty antes de la versi\u00f3n 4.1.71.Final omite los caracteres de control cuando est\u00e1n presentes al principio/fin del nombre de la cabecera. En su lugar, deber\u00eda fallar r\u00e1pidamente ya que estos no est\u00e1n permitidos por la especificaci\u00f3n y podr\u00edan llevar a un contrabando de peticiones HTTP. No hacer la validaci\u00f3n podr\u00eda causar que netty \"sanee\" los nombres de las cabeceras antes de reenviarlas a otro sistema remoto cuando se usa como proxy. Este sistema remoto ya no puede ver el uso inv\u00e1lido, y por lo tanto no hace la validaci\u00f3n por s\u00ed mismo. Los usuarios deben actualizar a la versi\u00f3n 4.1.71.Final"
          }
        ],
        "id": "CVE-2021-43797",
        "lastModified": "2026-06-17T04:11:27.417",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "MEDIUM",
              "cvssData": {
                "accessComplexity": "MEDIUM",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "NONE",
                "baseScore": 4.3,
                "confidentialityImpact": "NONE",
                "integrityImpact": "PARTIAL",
                "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N",
                "version": "2.0"
              },
              "exploitabilityScore": 8.6,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": true
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 3.6,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            },
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2021-12-09T19:15:07.960",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20220107-0003/"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2023/dsa-5316"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20220107-0003/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2023/dsa-5316"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-444"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-444"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-10T00:08:49+00:00",
      "cve": "CVE-2021-43797",
      "id": "CVE-2021-43797",
      "initial_release_date": "2021-12-09T00:00:00+00:00",
      "product_status:fixed": "103",
      "product_status:known_affected": "15",
      "product_status:known_not_affected": "3766",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "netty: control chars in header names may lead to HTTP request smuggling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-43797.json",
      "version": "3"
    }
  }
}



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.