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CVE-2018-18729: There is a heap-based buffer overflow vulnerability in the router's web server -- httpd.

CVE-2018-18729 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 5 affected products, including Tenda Ac7 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 on Tenda AC7 V15.03.06.44_CN, AC9 V15.03.05.19(6318)_CN, AC10 V15.03.06.23_CN, AC15 V15.03.05.19_CN, and AC18 V15.03.05.19(6318)_CN devices. There is a heap-based buffer overflow vulnerability in the router's web server -- httpd. While processing the 'mac' parameter for a post request, the value is directly used in a strcpy to a variable placed on the heap, which can leak sensitive information or even hijack program control flow.

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-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

Affected products

  • Tenda Ac7 Firmware: 15.03.06.44_cn
  • Tenda Ac9 Firmware: 15.03.05.19\(6318\)_cn
  • Tenda Ac10 Firmware: 15.03.06.23_cn
  • Tenda Ac15 Firmware: 15.03.05.19_cn
  • Tenda Ac18 Firmware: 15.03.05.19\(6318\)_cn

References