Quantum Secular Labs / Blog / Advisories

CVE-2018-18320: An attacker can execute arbitrary commands because exec.php has a popen call.

CVE-2018-18320 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 14 affected products, including Asuswrt Merlin Project Rt Ac5300 Firmware. 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

An issue was discovered in the Merlin.PHP component 0.6.6 for Asuswrt-Merlin devices. An attacker can execute arbitrary commands because exec.php has a popen call. NOTE: the vendor indicates that Merlin.PHP is designed only for use on a trusted intranet network, and intentionally allows remote code execution

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.

Affected products

  • Asuswrt Merlin Project Rt Ac5300 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac1900p Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac68u Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac68p Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac88u Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac66u B1 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac56u Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac3200 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac68uf Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac87 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac3100 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac1900 Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac86u Firmware: up to and including 380.70
  • Asuswrt Merlin Project Rt Ac2900 Firmware: up to and including 380.70

References