{"api_version":"1","generated_at":"2026-04-23T02:18:55+00:00","cve":"CVE-2019-16786","urls":{"html":"https://cve.report/CVE-2019-16786","api":"https://cve.report/api/cve/CVE-2019-16786.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2019-16786","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-16786"},"summary":{"title":"CVE-2019-16786","description":"Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: \"Transfer-Encoding: gzip, chunked\" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2019-12-20 23:15:00","updated_at":"2023-11-07 03:05:00"},"problem_types":["CWE-444"],"metrics":[],"references":[{"url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html","name":"[debian-lts-announce] 20220512 [SECURITY] [DLA 3000-1] waitress security update","refsource":"MLIST","tags":[],"title":"[SECURITY] [DLA 3000-1] waitress security update","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://access.redhat.com/errata/RHSA-2020:0720","name":"RHSA-2020:0720","refsource":"REDHAT","tags":[],"title":"Red Hat Customer Portal","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/","name":"FEDORA-2020-bdcc8ffc24","refsource":"FEDORA","tags":[],"title":"[SECURITY] Fedora 30 Update: python-waitress-1.4.3-1.fc30 - package-announce - Fedora Mailing-Lists","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html","name":"https://www.oracle.com/security-alerts/cpuapr2022.html","refsource":"MISC","tags":[],"title":"Oracle Critical Patch Update Advisory - April 2022","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/","name":"FEDORA-2020-65a7744e38","refsource":"","tags":[],"title":"[SECURITY] Fedora 31 Update: python-waitress-1.4.3-1.fc31 - package-announce - Fedora Mailing-Lists","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3","name":"https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3","refsource":"MISC","tags":["Patch","Third Party Advisory"],"title":"Merge pull request from GHSA-g2xc-35jw-c63p · Pylons/waitress@f11093a · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/","name":"FEDORA-2020-bdcc8ffc24","refsource":"","tags":[],"title":"[SECURITY] Fedora 30 Update: python-waitress-1.4.3-1.fc30 - package-announce - Fedora Mailing-Lists","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p","name":"https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p","refsource":"CONFIRM","tags":["Third Party Advisory"],"title":"HTTP Request Smuggling: Invalid Transfer-Encoding · Advisory · Pylons/waitress · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"0"},{"url":"https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes","name":"https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes","refsource":"MISC","tags":["Release Notes","Vendor Advisory"],"title":"Waitress — waitress 2.0.0 documentation","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/","name":"FEDORA-2020-65a7744e38","refsource":"FEDORA","tags":[],"title":"[SECURITY] Fedora 31 Update: python-waitress-1.4.3-1.fc31 - package-announce - Fedora Mailing-Lists","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2019-16786","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-16786","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"agendaless","cpe5":"waitress","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"1","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"agendaless","cpe5":"waitress","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"debian","cpe5":"debian_linux","cpe6":"9.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"fedoraproject","cpe5":"fedora","cpe6":"30","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"fedoraproject","cpe5":"fedora","cpe6":"31","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"oracle","cpe5":"communications_cloud_native_core_network_function_cloud_native_environment","cpe6":"1.10.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2019","cve_id":"16786","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"redhat","cpe5":"openstack","cpe6":"15","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[{"cve":"CVE-2019-16786","qid":"174724","title":"SUSE Enterprise Linux Security update for python-waitress (SUSE-SU-2020:3269-1)"},{"cve":"CVE-2019-16786","qid":"179276","title":"Debian Security Update for waitress (DLA 3000-1)"},{"cve":"CVE-2019-16786","qid":"296075","title":"Oracle Solaris 11.4 Support Repository Update (SRU) 21.69.0 Missing (CPUAPR2020)"},{"cve":"CVE-2019-16786","qid":"501368","title":"Alpine Linux Security Update for py3-waitress"},{"cve":"CVE-2019-16786","qid":"750599","title":"OpenSUSE Security Update for python-waitress (openSUSE-SU-2020:1922-1)"},{"cve":"CVE-2019-16786","qid":"750606","title":"OpenSUSE Security Update for python-waitress (openSUSE-SU-2020:1911-1)"},{"cve":"CVE-2019-16786","qid":"983107","title":"Python (pip) Security Update for waitress (GHSA-g2xc-35jw-c63p)"}]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2019-16786","STATE":"PUBLIC","TITLE":"HTTP Request Smuggling: Invalid Transfer-Encoding in Waitress"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"Waitress","version":{"version_data":[{"version_affected":"<=","version_name":"<= 1.3.1","version_value":"1.3.1"}]}}]},"vendor_name":"Pylons"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: \"Transfer-Encoding: gzip, chunked\" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0."}]},"impact":{"cvss":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')"}]}]},"references":{"reference_data":[{"refsource":"FEDORA","name":"FEDORA-2020-bdcc8ffc24","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/"},{"refsource":"FEDORA","name":"FEDORA-2020-65a7744e38","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/"},{"refsource":"REDHAT","name":"RHSA-2020:0720","url":"https://access.redhat.com/errata/RHSA-2020:0720"},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html","refsource":"MISC","name":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"name":"https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes","refsource":"MISC","url":"https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes"},{"name":"https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p","refsource":"CONFIRM","url":"https://github.com/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p"},{"name":"https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3","refsource":"MISC","url":"https://github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3"},{"refsource":"MLIST","name":"[debian-lts-announce] 20220512 [SECURITY] [DLA 3000-1] waitress security update","url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html"}]},"source":{"advisory":"GHSA-g2xc-35jw-c63p","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2019-12-20 23:15:00","lastModifiedDate":"2023-11-07 03:05:00","problem_types":["CWE-444"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:P/A:N","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":5},"severity":"MEDIUM","exploitabilityScore":10,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:agendaless:waitress:*:*:*:*:*:*:*:*","versionEndExcluding":"1.3.1","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:oracle:communications_cloud_native_core_network_function_cloud_native_environment:1.10.0:*:*:*:*:*:*:*","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:redhat:openstack:15:*:*:*:*:*:*:*","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2019","CveId":"16786","Ordinal":"156508","Title":"CVE-2019-16786","CVE":"CVE-2019-16786","Year":"2019"},"notes":[{"CveYear":"2019","CveId":"16786","Ordinal":"1","NoteData":"Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: \"Transfer-Encoding: gzip, chunked\" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.","Type":"Description","Title":null},{"CveYear":"2019","CveId":"16786","Ordinal":"2","NoteData":"2019-12-20","Type":"Other","Title":"Published"},{"CveYear":"2019","CveId":"16786","Ordinal":"3","NoteData":"2020-03-11","Type":"Other","Title":"Modified"}]}}}