CVE-2019-13344: An authentication bypass vulnerability in the CRUDLab WP Like Button plugin through 1.6.0 for WordPress allows unauthenticated attackers to change settings…

PriorityP355medium5.3CVSS 3.0

AVNACLPRNUINSUCNILAN

EXPLOIT

EPSS

45.09%

98.6th percentile

An authentication bypass vulnerability in the CRUDLab WP Like Button plugin through 1.6.0 for WordPress allows unauthenticated attackers to change settings. The contains() function in wp_like_button.php did not check if the current request is made by an authorized user, thus allowing any unauthenticated user to successfully update settings, as demonstrated by the wp-admin/admin.php?page=facebook-like-button each_page_url or code_snippet parameter.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
crudlab	wp_like_button	<= 1.6.0	—

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://localhost/wp/wp-admin/admin.php?page=facebook-like-button&edit=1↗

path/wp-admin/admin.php?page=facebook-like-button↗

filenamewp_like_button.php↗

commandcurl -k -i --raw -X POST -d "page=facebook-like-button&site_url=https%%3A%%2F%%2Flocalhost%%2Fwp&display[]=1&display[]=2&display[]=4&display[]=16&mobile=1&fb_app_id=&fb_app_admin=&kd=0&fblb_default_upload_image=&code_snippet=%%3C%%3Fphp+echo+fb_like_button()%%3B+%%3F%%3E&beforeafter=before&eachpage=url&each_page_url=https://hijack.com&language=en_US&width=65&position=center&layout=box_count&action=like&color=light&btn_size=small&faces=1&share=1&update_fblb="↗

→Detect unauthenticated POST requests to the WordPress admin plugin settings page for WP Like Button — any POST to /wp-admin/admin.php?page=facebook-like-button without a valid authenticated session cookie should be flagged as exploitation of CVE-2019-13344. ↗
→Alert on POST requests containing the parameter 'update_fblb' in the body targeting /wp-admin/admin.php?page=facebook-like-button, which is the trigger parameter used to save settings in the vulnerable plugin. ↗
→Monitor for the 'code_snippet' POST parameter being set to PHP code (e.g. containing '<?php') in requests to the WP Like Button admin page, which could indicate an attacker injecting arbitrary code via the unauthenticated settings update. ↗
→The vulnerable code path is the contains() function in wp_like_button.php; source code review or file integrity monitoring of this file can confirm whether the authorization check is absent. ↗

·The vulnerability affects WP Like Button plugin version 1.6.0 and below (including 1.5.0). The vendor released v1.6.0 but did not fix the issue; no patched version was available at time of disclosure. Detections should target all installs up to and including v1.6.0. ↗
·The exploit requires no authentication whatsoever — the POST request does not need any session cookie or nonce, making it trivially exploitable by any unauthenticated remote attacker. ↗

CVSS provenance

nvdv3.05.3MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N

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