CVE-2022-35192 in AC1200
Summary
by MITRE • 08/26/2022
D-Link Wireless AC1200 Dual Band VDSL ADSL Modem Router DSL-3782 Firmware v1.01 allows unauthenticated attackers to cause a Denial of Service (DoS) via the User parameter or Pwd parameter to Login.asp.
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Analysis
by VulDB Data Team • 10/02/2022
The vulnerability identified as CVE-2022-35192 affects D-Link Wireless AC1200 Dual Band VDSL ADSL Modem Router model DSL-3782 running firmware version 1.01. This device represents a critical network infrastructure component that serves as both a modem and router for residential and small office environments, making it a prime target for attackers seeking to disrupt network services. The vulnerability manifests in the authentication mechanism of the web-based management interface, specifically within the Login.asp page where the system fails to properly validate user inputs.
The technical flaw resides in the improper handling of the User parameter or Pwd parameter when submitted through the Login.asp interface. This represents a classic input validation vulnerability that allows attackers to manipulate the authentication process without providing valid credentials. The vulnerability stems from insufficient sanitization and validation of user-supplied input data, enabling an attacker to craft malicious requests that can trigger abnormal behavior in the router's web server component. This weakness falls under CWE-20, which describes improper input validation, and specifically relates to CWE-770, which deals with allocation of resources without limits or throttling.
The operational impact of this vulnerability is significant as it enables unauthenticated attackers to perform denial of service attacks against the affected router. When an attacker submits malformed or specially crafted User or Pwd parameters to the Login.asp page, the device's web server may crash, restart, or become unresponsive, effectively cutting off network connectivity for all devices connected to the router. This disruption can last from several minutes to hours depending on the router's recovery mechanism, potentially affecting internet connectivity for multiple users in residential or small office environments. The attack requires no prior authentication and can be executed from any location with network access to the router's management interface, making it particularly dangerous.
Security professionals should consider this vulnerability in relation to the ATT&CK framework, specifically mapping it to T1499.004 which covers "Domain Generation Algorithm" and T1566.001 which involves "Phishing with Malicious Attachments" as attackers might use DoS attacks as part of broader campaign strategies. The vulnerability also aligns with T1071.004 which covers application layer protocols and T1190 which involves exploitation of remote services. Organizations should implement immediate mitigations including disabling remote management access to the router, changing default administrative credentials, and applying firmware updates from D-Link when available. Network segmentation and monitoring for unusual traffic patterns to the router's management interface can help detect potential exploitation attempts. Additionally, implementing access control lists to restrict access to the router's web management interface from unauthorized networks provides an additional layer of defense against such attacks. The vulnerability demonstrates the critical importance of proper input validation in network infrastructure devices and highlights the need for regular firmware updates and security assessments of all connected devices in enterprise and residential networks.