CVE-2020-7357

published 2020-08-06

CVE-2020-7357: Cayin CMS suffers from an authenticated OS semi-blind command injection vulnerability using default credentials. This can be exploited to inject and execute…

Priority P1 78 critical 9.9 CVSS 3.1

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

EXPLOIT

Cayin CMS suffers from an authenticated OS semi-blind command injection vulnerability using default credentials. This can be exploited to inject and execute arbitrary shell commands as the root user through the 'NTP_Server_IP' HTTP POST parameter in system.cgi page. This issue affects several branches and versions of the CMS application, including CME-SE, CMS-60, CMS-40, CMS-20, and CMS version 8.2, 8.0, and 7.5.

Affected

14 ranges

Vendor	Product	Version range	Fixed in
cayin_technology	cayin_cms	—	—
cayin_technology	cayin_cms	—	—
cayin_technology	cayin_cms	—	—
cayin_technology	cayin_cms-20	9.0 Build 14917 – 9.0 Build 14917	—
cayin_technology	cayin_cms-40	9.0 Build 14917 – 9.0 Build 14917	—
cayin_technology	cayin_cms-60	11.0 Build 19025 – 11.0 Build 19025	—
cayin_technology	cayin_cms-se	11.0 Build 19179 – 11.0 Build 19179	—
cayintech	cms	—	—
cayintech	cms	—	—
cayintech	cms	—	—
cayintech	cms-20_firmware	—	—
cayintech	cms-40_firmware	—	—
cayintech	cms-60_firmware	—	—
cayintech	cms-se_firmware	—	—

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

path /system.cgi↗

path /system_service.cgi↗

other NTP_Server_IP↗

other ntpIp↗

• → Monitor HTTP POST requests to system.cgi or system_service.cgi targeting the NTP_Server_IP / ntpIp parameter for shell metacharacters or command injection payloads. ↗
• → Exploitation uses repeated/chunked HTTP requests to the ntpIp parameter due to field size limitations — look for an unusual volume of small POST requests to system_service.cgi from the same source. ↗
• → Successful exploitation results in root-level code execution on the underlying Linux host; alert on unexpected root-owned processes spawned by the web server process. ↗
• → Exploitation is authenticated using default credentials — detect use of default Cayin CMS credentials followed by POST activity to the CGI endpoints. ↗

• · The exploit targets Cayin CMS-SE built for Ubuntu 16.04; Ubuntu 20.04 is noted as failing to install correctly, so the environment is relatively static and predictable across targets. ↗
• · Affected versions span multiple product lines (CME-SE, CMS-60, CMS-40, CMS-20) and software versions 7.5, 8.0, and 8.2, as well as all CMS releases up to and including 11.0. ↗

CVSS provenance

nvd v3.1 9.9 CRITICAL CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

nvd v2.0 9.0 CRITICAL AV:N/AC:L/Au:S/C:C/I:C/A:C

CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.

CWE-78