High severity · published Oct 23, 2019
CVE-2019-18277
A flaw was found in HAProxy before 2.0.6
7.5
CVSS
10.1%
EPSS
No
On KEV
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).
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)10.1% · higher than 96% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HA
Haproxy · Haproxy
before 2.0.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-18277
CVE.org
https://www.cve.org/CVERecord?id=CVE-2019-18277
lists.opensuse.org
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00016.html
lists.opensuse.org
http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00019.html
git.haproxy.org
https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=196a7df44d8129d1adc795da020b722614d6a581
lists.debian.org
https://lists.debian.org/debian-lts-announce/2022/05/msg00045.html
Exploit
https://nathandavison.com/blog/haproxy-http-request-smuggling
usn.ubuntu.com
https://usn.ubuntu.com/4174-1/
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