CVE-2018-13981

published 2018-07-16

CVE-2018-13981: The websites that were built from Zeta Producer Desktop CMS before 14.2.1 are vulnerable to unauthenticated remote code execution due to a default component…

Priority P2 75 critical 9.8 CVSS 3.0

AV N AC L PR N UI N S U C H I H A H

EXPLOIT

The websites that were built from Zeta Producer Desktop CMS before 14.2.1 are vulnerable to unauthenticated remote code execution due to a default component that permits arbitrary upload of PHP files, because the formmailer widget blocks .php files but not .php5 or .phtml files. This is related to /assets/php/formmailer/SendEmail.php and /assets/php/formmailer/functions.php.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
zeta-producer	zeta_producer_desktop_cms	< 14.2.1	14.2.1

Detection & IOCs extracted from sources · hover to see the quote

path /assets/php/formmailer/SendEmail.php↗

path /assets/php/formmailer/functions.php↗

path /assets/php/filebrowser/filebrowser.main.php↗

filename sectest.php5↗

url http://target/assets/php/filebrowser/filebrowser.main.php?file=../../../../../../../../../../etc/passwd&do=download↗

url http://target/assets/php/filebrowser/filebrowser.main.php?file=../../../../../../../../../../etc&do=list↗

port 9153↗

• → Detect upload of .php5 or .phtml files to the formmailer upload path; the widget blocks .php but not these alternative executable extensions. ↗
• → Monitor for POST requests to /assets/php/formmailer/SendEmail.php containing multipart file uploads with .php5 or .phtml extensions. ↗
• → Uploaded webshell directories follow the pattern 'upload_<uniqid()>' under /assets/php/formmailer/; monitor for new directories matching this pattern. ↗
• → Detect path traversal attempts via the 'file' parameter in GET requests to /assets/php/filebrowser/filebrowser.main.php with sequences of '../'. ↗
• → Alert on unauthenticated access to the Zeta Producer local web server on TCP port 9153, which exposes the same RCE attack surface. ↗

• · The formmailer widget is enabled by default, meaning all sites built with vulnerable versions are exposed without any additional configuration by the victim. ↗
• · Upgrading the CMS alone is insufficient; the affected widgets must also be updated or rebuilt in each website project, otherwise the vulnerable files remain deployed. ↗
• · If directory listing is disabled, the attacker can still brute-force the uniqid-based upload directory name; exploitation was demonstrated in ~20 seconds on a local server. ↗

CVSS provenance

nvd v3.0 9.8 CRITICAL CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd v2.0 7.5 HIGH AV:N/AC:L/Au:N/C:P/I:P/A:P

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