{"id":"CVE-2019-18277","details":"A flaw was found in HAProxy before 2.0.6. In legacy mode, messages featuring a transfer-encoding header missing the \"chunked\" value were not being correctly rejected. The impact was limited but if combined with the \"http-reuse always\" setting, it could be used to help construct an HTTP request smuggling attack against a vulnerable component employing a lenient parser that would ignore the content-length header as soon as it saw a transfer-encoding one (even if not entirely valid according to the specification).","modified":"2026-03-15T22:27:30.068459Z","published":"2019-10-23T14:15:10.557Z","related":["SUSE-SU-2019:3125-1","SUSE-SU-2019:3126-1","SUSE-SU-2019:3288-1","openSUSE-SU-2019:2626-1","openSUSE-SU-2019:2645-1","openSUSE-SU-2024:10839-1"],"references":[{"type":"WEB","url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00019.html"},{"type":"WEB","url":"https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=196a7df44d8129d1adc795da020b722614d6a581"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2022/05/msg00045.html"},{"type":"WEB","url":"https://usn.ubuntu.com/4174-1/"},{"type":"WEB","url":"https://www.mail-archive.com/haproxy%40formilux.org/msg34926.html"},{"type":"WEB","url":"http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00016.html"},{"type":"EVIDENCE","url":"https://nathandavison.com/blog/haproxy-http-request-smuggling"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/haproxy/haproxy","events":[{"introduced":"0"},{"fixed":"b57f10996625e073650a5da8ef01e11cfe9018ea"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"2.0.6"}]}}],"versions":["v1.0.0","v1.0.1","v1.0.2","v1.1.0","v1.1.1","v1.1.10","v1.1.11","v1.1.12","v1.1.13","v1.1.14","v1.1.15","v1.1.16","v1.1.17","v1.1.18","v1.1.19","v1.1.2","v1.1.20","v1.1.21","v1.1.22","v1.1.23","v1.1.24","v1.1.25","v1.1.26","v1.1.27","v1.1.3","v1.1.4","v1.1.5","v1.1.6","v1.1.7","v1.1.8","v1.1.9","v1.2.0","v1.2.1","v1.2.1-pre1","v1.2.1-pre2","v1.2.1-pre3","v1.2.10","v1.2.10.1","v1.2.11","v1.2.11.1","v1.2.12","v1.2.13","v1.2.13.1","v1.2.14","v1.2.2","v1.2.3","v1.2.4","v1.2.5","v1.2.5-pre1","v1.2.5-pre2","v1.2.5-pre3","v1.2.5-pre4","v1.2.5.1","v1.2.5.2","v1.2.6","v1.2.6-pre4","v1.2.6-pre5","v1.2.7","v1.2.7.1","v1.2.7rc","v1.2.8","v1.2.9","v1.3.0","v1.3.1","v1.3.10","v1.3.10.1","v1.3.10.2","v1.3.11","v1.3.11.1","v1.3.11.2","v1.3.11.3","v1.3.11.4","v1.3.12","v1.3.13","v1.3.14","v1.3.15","v1.3.16","v1.3.16-rc1","v1.3.16-rc2","v1.3.17","v1.3.18","v1.3.2","v1.3.3","v1.3.4","v1.3.5","v1.3.6","v1.3.6.1","v1.3.7","v1.3.8","v1.3.8.1","v1.3.8.2","v1.3.9","v1.4-dev0","v1.4-dev1","v1.4-dev2","v1.4-dev3","v1.4-dev4","v1.4-dev5","v1.4-dev6","v1.4-dev7","v1.4-dev8","v1.4-rc1","v1.4.0","v1.4.1","v1.4.2","v1.4.3","v1.4.4","v1.4.5","v1.4.6","v1.5-dev10","v1.5-dev12","v1.5-dev13","v1.5-dev14","v1.5-dev15","v1.5-dev16","v1.5-dev17","v1.5-dev18","v1.5-dev19","v1.5-dev20","v1.5-dev21","v1.5-dev22","v1.5-dev23","v1.5-dev24","v1.5-dev25","v1.5-dev26","v1.5-dev8","v1.5-dev9","v1.5.0","v1.6-dev0","v1.6-dev1","v1.6-dev2","v1.6-dev3","v1.6-dev4","v1.6-dev5","v1.6-dev6","v1.6-dev7","v1.6.0","v1.7-dev0","v1.7-dev1","v1.7-dev2","v1.7-dev3","v1.7-dev4","v1.7-dev5","v1.7-dev6","v1.7.0","v1.8-dev0","v1.8-dev1","v1.8-dev2","v1.8-dev3","v1.8-rc1","v1.8-rc2","v1.8-rc3","v1.8-rc4","v1.8.0","v1.9-dev0","v1.9-dev1","v1.9-dev10","v1.9-dev11","v1.9-dev2","v1.9-dev3","v1.9-dev4","v1.9-dev5","v1.9-dev6","v1.9-dev7","v1.9-dev8","v1.9-dev9","v1.9.0","v2.0-dev0","v2.0-dev1","v2.0-dev2","v2.0-dev3","v2.0-dev4","v2.0-dev5"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18277.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}