cbcvebase.
CVE-2020-28037
published 2020-11-02

CVE-2020-28037: is_blog_installed in wp-includes/functions.php in WordPress before 5.5.2 improperly determines whether WordPress is already installed, which might allow an…

PriorityP260critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
7.74%
93.9th percentile
is_blog_installed in wp-includes/functions.php in WordPress before 5.5.2 improperly determines whether WordPress is already installed, which might allow an attacker to perform a new installation, leading to remote code execution (as well as a denial of service for the old installation).

Affected

10 ranges
VendorProductVersion rangeFixed in
debiandebian_linux
debianwordpress< wordpress 5.5.3+dfsg1-1 (bookworm)wordpress 5.5.3+dfsg1-1 (bookworm)
fedoraprojectfedora
fedoraprojectfedora
fedoraprojectfedora
wordpresswordpress< 5.5.25.5.2
wordpresswordpress>= 0 < 5.5.3+dfsg1-15.5.3+dfsg1-1
wordpresswordpress>= 0 < 5.5.3+dfsg1-15.5.3+dfsg1-1
wordpresswordpress>= 0 < 5.5.3+dfsg1-15.5.3+dfsg1-1
wordpresswordpress>= 0 < 5.5.3+dfsg1-15.5.3+dfsg1-1

Detection & IOCsextracted from sources · hover to see the quote

pathwp-includes/functions.php
  • Monitor for unexpected access to the WordPress installation endpoint (wp-admin/install.php) on already-installed WordPress instances, which may indicate an attacker attempting to trigger a new installation via the is_blog_installed() logic flaw.
  • The upstream patch commit 2ca15d1e5ce70493c5c0c096ca0c76503d6da07c in the WordPress GitHub repository can be used to diff the vulnerable vs. patched is_blog_installed() logic for building precise detection rules.
  • WPScan vulnerability ID 10450 can be used to cross-reference scanner findings for this specific CVE.
  • ·Vulnerability only affects WordPress installations running versions prior to 5.5.2; instances already patched to 5.5.2 or later (or Debian package 5.5.3+dfsg1-1) are not affected.
  • ·The attack vector requires the attacker to be able to reach the WordPress installation routine; network-level controls restricting access to wp-admin/install.php on production sites reduce exposure.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_debian9.8CRITICAL
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