Inconsistent interpretation of HTTP requests in lua-nginx-module and OpenResty - CVE-2020-11724

Vulnerability identifier: #VU46107

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-11724

CWE-ID: CWE-444

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP requests in ngx_http_lua_subrequest.c in lua-nginx-module for OpenResy. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

lua-nginx-module
OpenResty
nginx (Debian package)
nginx-light (Ubuntu package)
nginx-full (Ubuntu package)
nginx-core (Ubuntu package)
nginx-extras (Ubuntu package)
libnginx-mod-http-lua (Ubuntu package)
VMware Tanzu Operations Manager
Ubuntu

Install update from vendor's website.

lua-nginx-module - update to 0.10.17
nginx (Debian package) - update to 1.14.2-2+deb10u3
VMware Tanzu Operations Manager - addressed in versions 2.7.25, 2.8.16, 2.9.12, 2.10.3
nginx-light (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 1.14.0-0ubuntu1.10, 1.18.0-0ubuntu1.3, 1.18.0-6ubuntu11.1, 1.18.0-6ubuntu14.1
nginx-full (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 1.14.0-0ubuntu1.10, 1.18.0-0ubuntu1.3
nginx-core (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 1.14.0-0ubuntu1.10, 1.18.0-0ubuntu1.3, 1.18.0-6ubuntu11.1, 1.18.0-6ubuntu14.1
nginx-extras (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 1.14.0-0ubuntu1.10, 1.18.0-0ubuntu1.3, 1.18.0-6ubuntu11.1, 1.18.0-6ubuntu14.1
libnginx-mod-http-lua (Ubuntu package) - addressed in versions 1.14.0-0ubuntu1.10, 1.18.0-0ubuntu1.3

• https://github.com/openresty/lua-nginx-module/commit/9ab38e8ee35fc08a57636b1b6190dca70b0076fa
• https://github.com/openresty/openresty/blob/4e8b4c395f842a078e429c80dd063b2323999957/patches/ngx_http_lua-0.10.15-fix_location_capture_content_length_chunked.patch
• https://lists.debian.org/debian-lts-announce/2020/07/msg00014.html
• https://www.debian.org/security/2020/dsa-4750

• HTTP request smuggling in lua-nginx-module for OpenResty
• Debian update for nginx
• Ubuntu update for nginx
• Ubuntu update for nginx
• VMware Tanzu Operations Manager update for nginx
• Ubuntu update for nginx