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CVE-2018-25318: Tenda A300 Firmware: Authentication bypass

CVE-2018-25318 is rated critical with a CVSS v3.1 base score of 9.8 and affects Tenda A300 Firmware, along with 1 other product in NVD’s configuration data. 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

Tenda FH303/A300 firmware V5.07.68_EN contains a session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient cookie validation. Attackers can send GET requests to the /goform/AdvSetDns endpoint with a crafted admin cookie to change DNS servers and redirect user traffic to malicious sites.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/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-290: Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Affected products

Tenda A300 Firmware: 5.07.68_en
Tenda Fh303 Firmware: 5.07.68_en