Quantum Secular Labs / Blog / Advisories

CVE-2017-11420: Stack-based buffer overflow in ASUS_Discovery.c in networkmap in Asuswrt-Merlin firmware for ASUS devices…

CVE-2017-11420 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 28 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

Stack-based buffer overflow in ASUS_Discovery.c in networkmap in Asuswrt-Merlin firmware for ASUS devices and ASUS firmware for ASUS RT-AC5300, RT_AC1900P, RT-AC68U, RT-AC68P, RT-AC88U, RT-AC66U, RT-AC66U_B1, RT-AC58U, RT-AC56U, RT-AC55U, RT-AC52U, RT-AC51U, RT-N18U, RT-N66U, RT-N56U, RT-AC3200, RT-AC3100, RT_AC1200GU, RT_AC1200G, RT-AC1200, RT-AC53, RT-N12HP, RT-N12HP_B1, RT-N12D1, RT-N12+, RT_N12+_PRO, RT-N16, and RT-N300 devices allows remote attackers to execute arbitrary code via long device information that is mishandled during a strcat to a device list.

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-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.

Affected products

  • Asuswrt Merlin Project Rt Ac5300 Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac1900p Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac68u Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac68p Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac88u Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac66u Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac66u B1 Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac58u Firmware: up to and including 3.0.0.4.380.7485
  • Asuswrt Merlin Project Rt Ac56u Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt Ac55u Firmware: up to and including 3.0.0.4.380.7378
  • Asuswrt Merlin Project Rt Ac52u Firmware: up to and including 3.0.0.4.380.4180
  • Asuswrt Merlin Project Rt Ac51u Firmware: up to and including 3.0.0.4.380.7378
  • Asuswrt Merlin Project Rt N18u Firmware: up to and including 3.0.0.4.380.7743
  • Asuswrt Merlin Project Rt N66u Firmware: up to and including 3.0.0.4.380.7378
  • Asuswrt Merlin Project Rt N56u Firmware: up to and including 3.0.0.4.378.7177

References