cbcvebase.
CVE-2019-20372
published 2020-01-09

CVE-2019-20372: NGINX before 1.17.7, with certain error_page configurations, allows HTTP request smuggling, as demonstrated by the ability of an attacker to read unauthorized…

PriorityP338medium5.3CVSS 3.1
AVNACLPRNUINSUCLINAN
EPSS
14.96%
96.3th percentile
NGINX before 1.17.7, with certain error_page configurations, allows HTTP request smuggling, as demonstrated by the ability of an attacker to read unauthorized web pages in environments where NGINX is being fronted by a load balancer.

Affected

13 ranges
VendorProductVersion rangeFixed in
applexcode< 13.013.0
applexcode
canonicalubuntu_linux
debiannginx< nginx 1.16.1-3 (bookworm)nginx 1.16.1-3 (bookworm)
f5nginx< 1.17.71.17.7
f5nginx>= 0 < 1.16.1-31.16.1-3
f5nginx>= 0 < 1.16.1-31.16.1-3
f5nginx>= 0 < 1.16.1-31.16.1-3
f5nginx>= 0 < 1.16.1-31.16.1-3
msrccbl_mariner_1.0_arm
msrccbl_mariner_1.0_x64
msrccm1_nginx_1.16.1-4_on_cbl_mariner_1.0
opensuseleap

Detection & IOCsextracted from sources · hover to see the quote

versionnginx < 1.17.7
  • Look for nginx versions 1.17.6 and earlier in HTTP response headers, which are vulnerable to HTTP request smuggling via error_page redirect configurations
  • The vulnerability is only triggered when nginx uses error_page with a URL redirect (302); configurations using named locations (e.g., error_page 401 @401) are NOT vulnerable and can be used as a baseline for safe config detection
  • Detect HTTP request smuggling attempts targeting nginx error_page redirect configurations, particularly in environments where nginx is fronted by a load balancer
  • ·Ansible Tower 3.5 and 3.6 are not vulnerable by default because they do not use the error_page variable in nginx configuration, but they ship vulnerable nginx versions (1.14 and 1.16) that could become vulnerable if configuration is modified
  • ·Red Hat CloudForms Management Engine 5.9 and 5.10 are not vulnerable by default (no error_page redirect in config) but ship vulnerable nginx versions 1.10 and 1.14 respectively; CloudForms 5.11 does not use nginx at all
  • ·Red Hat Quay is not affected because its nginx error_page configuration uses named locations (e.g., error_page 404 /404.html) rather than 302 redirects

CVSS provenance

nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:P/I:N/A:N
osv5.3MEDIUM
vendor_debian5.3LOW
vendor_msrc5.3MEDIUM
vendor_redhat5.3MEDIUM
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