CVE-2025-1852 in EX1800T
Summary
by MITRE • 03/03/2025
A vulnerability has been found in Totolink EX1800T 9.1.0cu.2112_B20220316 and classified as critical. This vulnerability affects the function loginAuth of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument password leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 03/03/2025
The vulnerability identified as CVE-2025-1852 represents a critical buffer overflow flaw in the Totolink EX1800T router firmware version 9.1.0cu.2112_B20220316. This issue resides within the loginAuth function of the /cgi-bin/cstecgi.cgi component, which serves as a critical interface for authentication processes in the device's web management portal. The vulnerability specifically manifests when processing the password argument, creating an exploitable condition that allows attackers to manipulate input data beyond the allocated buffer boundaries. The exposure of this flaw in the authentication mechanism fundamentally compromises the device's security posture and provides attackers with potential pathways for unauthorized access to the router's administrative functions.
The technical exploitation of this buffer overflow vulnerability occurs through remote manipulation of the password parameter during the login process. When an attacker submits a specially crafted password string that exceeds the allocated buffer size, the excess data overflows into adjacent memory locations, potentially corrupting critical program execution flow or allowing arbitrary code injection. This type of vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and may also exhibit characteristics of CWE-122, heap-based buffer overflow, depending on the specific memory allocation patterns within the affected application. The remote attack vector eliminates the need for physical access to the device, making the vulnerability particularly dangerous as it can be exploited from any network location with access to the router's web interface.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with complete administrative control over the affected router. Successful exploitation could enable attackers to modify network configurations, redirect traffic through malicious proxies, install backdoors, or use the compromised device as a pivot point for attacking other systems within the local network. This represents a significant threat to network security as the router serves as a gateway device, potentially allowing attackers to bypass firewalls, intercept communications, or establish persistent access to the network. The public disclosure of the exploit further amplifies the risk, as it provides adversaries with readily available tools and techniques to target vulnerable installations without requiring advanced exploitation skills. Network defenders face the challenge of identifying and patching affected devices across potentially large deployments, as the vulnerability affects a specific model and firmware version combination that may be widely deployed in enterprise and residential environments.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from the vendor, as the most effective solution involves patching the underlying code to properly validate input lengths before processing. Network administrators should implement network segmentation to limit the exposure of these devices to external networks and consider disabling unnecessary web management interfaces when not actively required for configuration tasks. Additional protective measures include implementing strong authentication practices such as multi-factor authentication where available, monitoring for unusual login patterns or failed authentication attempts, and maintaining detailed network logs to detect potential exploitation attempts. The vulnerability also highlights the importance of secure coding practices and input validation in embedded systems, as the lack of proper bounds checking in the authentication function created the exploitable condition. Organizations should conduct comprehensive vulnerability assessments to identify other potentially affected devices within their network infrastructure and consider implementing network access control lists to restrict access to administrative interfaces to trusted IP addresses only.