CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCVE-2019-18277
High (7.5) in haproxy haproxy. EPSS 10% chance of exploitation in the next 30 days.
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).
Severity
- EPSS
- 10% chance of exploitation in the next 30 days; higher than 95% of CVEs (scores of 2026-10-31)
- CWE
- CWE-444
- Published
- Modified
- Record from
- the NVD, synced
Affected
- haproxy:haproxy
References
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00016.html
- http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00019.html
- https://git.haproxy.org/?p=haproxy-2.0.git%3Ba=commit%3Bh=196a7df44d8129d1adc795da020b722614d6a581
- https://lists.debian.org/debian-lts-announce/2022/05/msg00045.html
- https://nathandavison.com/blog/haproxy-http-request-smuggling