Quantum Secular Labs / Blog / Advisories

CVE-2018-10085: CMS Made Simple: Remote code execution

CVE-2018-10085 is rated critical with a CVSS v3.0 base score of 9.8 and affects CMS Made Simple. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

CMS Made Simple (CMSMS) through 2.2.6 allows PHP object injection because of an unserialize call in the _get_data function of \lib\classes\internal\class.LoginOperations.php. By sending a crafted cookie, a remote attacker can upload and execute code, or delete files.

Severity breakdown

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

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-502: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected products

  • CMS Made Simple: up to and including 2.2.6

References