CVE-2019-18277
HIGHHAProxy < 2.0.6 - HTTP Request Smuggling via Transfer-Encoding Header
Title source: llmDescription
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).
References (7)
Core 7
Core References
Mailing List x_refsource_misc
https://www.mail-archive.com/haproxy%40formilux.org/msg34926.html
Exploit, Third Party Advisory x_refsource_misc
https://nathandavison.com/blog/haproxy-http-request-smuggling
Various Sources x_refsource_misc
https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=196a7df44d8129d1adc795da020b722614d6a581
Vendor Advisory vendor-advisory
x_refsource_ubuntu
https://usn.ubuntu.com/4174-1/
Mailing List vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00016.html
Mailing List vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00019.html
Mailing List mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2022/05/msg00045.html
Scores
CVSS v3
7.5
EPSS
0.1002
EPSS Percentile
95.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Details
CWE
CWE-444
Status
published
Products (1)
haproxy/haproxy
< 2.0.6
Published
Oct 23, 2019
Tracked Since
Feb 18, 2026