CVE-2019-18277 Other in n/a

High 7.5 Published Updated

Attackers can exploit HTTP request smuggling in HAProxy legacy mode with specific reuse settings to bypass security controls.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2019-18277?

CVE-2019-18277 is a high-severity vulnerability in n/a, published on 23 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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).

Weakness: CWE-444

Which versions are affected by CVE-2019-18277?

It affects 1 product.

Linux distribution packages (13)
haproxy SUSE:HPE Helion OpenStack 8All versions1.6.11-11.3.1
haproxy SUSE:Linux Enterprise High Availability Extension 12 SP3All versions1.6.11-11.3.1
haproxy SUSE:Linux Enterprise High Availability Extension 12 SP4All versions1.6.11-11.3.1
haproxy SUSE:Linux Enterprise High Availability Extension 12 SP5All versions1.6.11-11.3.1
haproxy SUSE:Linux Enterprise High Availability Extension 15All versions2.0.10+git0.ac198b92-3.15.1
haproxy SUSE:Linux Enterprise High Availability Extension 15 SP1All versions2.0.10+git0.ac198b92-8.8.1
haproxy SUSE:OpenStack Cloud 7All versions1.6.11-11.3.1
haproxy SUSE:OpenStack Cloud 8All versions1.6.11-11.3.1
haproxy SUSE:OpenStack Cloud 9All versions1.6.11-11.3.1
haproxy SUSE:OpenStack Cloud Crowbar 8All versions1.6.11-11.3.1
haproxy SUSE:OpenStack Cloud Crowbar 9All versions1.6.11-11.3.1
haproxy openSUSE:Leap 15.0All versions2.0.10+git0.ac198b92-lp150.2.16.1
haproxy openSUSE:Leap 15.1All versions2.0.10+git0.ac198b92-lp151.2.6.1

Products include Haproxy Haproxy.

How do I fix CVE-2019-18277?

Upgrade to a fixed version.

Is CVE-2019-18277 being exploited?

There is no known exploitation of CVE-2019-18277 in the wild and no public exploit code.

Sources

Also known as CLSA-2026-1776336742, CLSA-2026-1776337242, DEBIAN-CVE-2019-18277, GHSA-7r84-r685-grmg, SUSE-SU-2019:3125-1, SUSE-SU-2019:3126-1 and 5 more.

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