Vulnerabilities > CVE-2019-16785 - HTTP Request Smuggling vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
HIGH Availability impact
NONE Summary
Waitress through version 1.3.1 implemented a "MAY" part of the RFC7230 which states: "Although the line terminator for the start-line and header fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any preceding CR." Unfortunately if a front-end server does not parse header fields with an LF the same way as it does those with a CRLF it can lead to the front-end and the back-end server parsing the same HTTP message in two different ways. This can lead to a potential for HTTP request smuggling/splitting whereby Waitress may see two requests while the front-end server only sees a single HTTP message. This issue is fixed in Waitress 1.4.0.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 2 | |
| Application | 1 | |
| Application | 1 | |
| OS | 1 | |
| OS | 2 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- HTTP Request Splitting HTTP Request Splitting (also known as HTTP Request Smuggling) is an attack pattern where an attacker attempts to insert additional HTTP requests in the body of the original (enveloping) HTTP request in such a way that the browser interprets it as one request but the web server interprets it as two. There are several ways to perform HTTP request splitting attacks. One way is to include double Content-Length headers in the request to exploit the fact that the devices parsing the request may each use a different header. Another way is to submit an HTTP request with a "Transfer Encoding: chunked" in the request header set with setRequestHeader to allow a payload in the HTTP Request that can be considered as another HTTP Request by a subsequent parsing entity. A third way is to use the "Double CR in an HTTP header" technique. There are also a few less general techniques targeting specific parsing vulnerabilities in certain web servers.
- HTTP Request Smuggling HTTP Request Smuggling results from the discrepancies in parsing HTTP requests between HTTP entities such as web caching proxies or application firewalls. Entities such as web servers, web caching proxies, application firewalls or simple proxies often parse HTTP requests in slightly different ways. Under specific situations where there are two or more such entities in the path of the HTTP request, a specially crafted request is seen by two attacked entities as two different sets of requests. This allows certain requests to be smuggled through to a second entity without the first one realizing it.
Nessus
NASL family Fedora Local Security Checks NASL id FEDORA_2020-BDCC8FFC24.NASL description Update to 1.4.3, fixing CVE-2019-16786 CVE-2019-16785 CVE-2019-16789 and adding various other hardening features. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-03-18 modified 2020-02-26 plugin id 134057 published 2020-02-26 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/134057 title Fedora 30 : python-waitress (2020-bdcc8ffc24) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2020-bdcc8ffc24. # include("compat.inc"); if (description) { script_id(134057); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/02"); script_cve_id("CVE-2019-16785", "CVE-2019-16786", "CVE-2019-16789"); script_xref(name:"FEDORA", value:"2020-bdcc8ffc24"); script_name(english:"Fedora 30 : python-waitress (2020-bdcc8ffc24)"); script_summary(english:"Checks rpm output for the updated package."); script_set_attribute( attribute:"synopsis", value:"The remote Fedora host is missing a security update." ); script_set_attribute( attribute:"description", value: "Update to 1.4.3, fixing CVE-2019-16786 CVE-2019-16785 CVE-2019-16789 and adding various other hardening features. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues." ); script_set_attribute( attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2020-bdcc8ffc24" ); script_set_attribute( attribute:"solution", value:"Update the affected python-waitress package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:python-waitress"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/12/20"); script_set_attribute(attribute:"patch_publication_date", value:"2020/02/25"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/26"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Fedora Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/RedHat/release"); if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora"); os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release); if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora"); os_ver = os_ver[1]; if (! preg(pattern:"^30([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 30", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC30", reference:"python-waitress-1.4.3-1.fc30")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_WARNING, extra : rpm_report_get() ); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "python-waitress"); }NASL family Fedora Local Security Checks NASL id FEDORA_2020-65A7744E38.NASL description Update to 1.4.3, fixing CVE-2019-16786 CVE-2019-16785 CVE-2019-16789 and adding various other hardening features. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-03-18 modified 2020-02-27 plugin id 134097 published 2020-02-27 reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/134097 title Fedora 31 : python-waitress (2020-65a7744e38) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory FEDORA-2020-65a7744e38. # include("compat.inc"); if (description) { script_id(134097); script_version("1.2"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/02"); script_cve_id("CVE-2019-16785", "CVE-2019-16786", "CVE-2019-16789"); script_xref(name:"FEDORA", value:"2020-65a7744e38"); script_name(english:"Fedora 31 : python-waitress (2020-65a7744e38)"); script_summary(english:"Checks rpm output for the updated package."); script_set_attribute( attribute:"synopsis", value:"The remote Fedora host is missing a security update." ); script_set_attribute( attribute:"description", value: "Update to 1.4.3, fixing CVE-2019-16786 CVE-2019-16785 CVE-2019-16789 and adding various other hardening features. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues." ); script_set_attribute( attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2020-65a7744e38" ); script_set_attribute( attribute:"solution", value:"Update the affected python-waitress package." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:python-waitress"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:31"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/12/20"); script_set_attribute(attribute:"patch_publication_date", value:"2020/02/26"); script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/27"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Fedora Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/RedHat/release"); if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora"); os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release); if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora"); os_ver = os_ver[1]; if (! preg(pattern:"^31([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 31", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC31", reference:"python-waitress-1.4.3-1.fc31")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_WARNING, extra : rpm_report_get() ); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "python-waitress"); }
Redhat
| advisories |
| ||||
| rpms | python3-waitress-0:1.4.2-1.el8ost |
References
- https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57p
- https://github.com/Pylons/waitress/commit/8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba
- https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
- https://access.redhat.com/errata/RHSA-2020:0720
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/