CVE-2018-0522 in WXR-1900DHP2
Summary
by MITRE
Buffer overflow in Buffalo WXR-1900DHP2 firmware Ver.2.48 and earlier allows an attacker to execute arbitrary code via a specially crafted file.
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Analysis
by VulDB Data Team • 01/12/2020
The vulnerability identified as CVE-2018-0522 represents a critical buffer overflow flaw discovered in the Buffalo WXR-1900DHP2 wireless router firmware versions 2.48 and earlier. This issue stems from improper input validation within the firmware's handling of specially crafted files, creating a pathway for remote code execution that could be exploited by malicious actors. The affected device operates under the Buffalo brand, which is widely deployed in both residential and small office environments, making this vulnerability particularly concerning from a cybersecurity perspective. The buffer overflow occurs when the device processes external files without adequate bounds checking, allowing an attacker to overwrite adjacent memory locations and potentially gain unauthorized control over the system.
This vulnerability maps directly to CWE-121, which describes a stack-based buffer overflow condition where insufficient bounds checking allows an attacker to write past the end of allocated buffer space. The technical implementation flaw manifests in the firmware's file processing routines where input data is not properly validated against buffer size limitations. When an attacker submits a maliciously crafted file, the system's memory management fails to prevent the overflow, resulting in unpredictable behavior that can be leveraged to execute arbitrary code. The attack vector is particularly dangerous as it allows for remote exploitation, meaning an attacker does not need physical access to the device to carry out the attack. The vulnerability exists at the application layer within the router's firmware, specifically in the file handling components that process user-supplied data without proper sanitization mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized access, as successful exploitation could enable attackers to gain full administrative control over the affected router. This compromised device could then serve as a pivot point for broader network attacks, allowing threat actors to perform man-in-the-middle attacks, redirect traffic, or establish persistent backdoors within the network infrastructure. Network defenders face significant challenges as the vulnerability affects a widely deployed consumer-grade device that often remains unpatched due to user unawareness or lack of automatic update mechanisms. The implications are particularly severe in enterprise environments where such devices may be connected to critical network segments, potentially exposing sensitive data and systems to unauthorized access.
Mitigation strategies for this vulnerability should encompass multiple layers of defense to protect against exploitation attempts. The primary recommendation involves immediate firmware updates from Buffalo to versions that address the buffer overflow issue, though users must ensure they download updates from official sources to avoid potential supply chain attacks. Network segmentation and access control measures should be implemented to limit the potential damage if a device is compromised, including restricting router management access to trusted IP ranges and implementing strong authentication mechanisms. Additionally, security monitoring should include detection of unusual network traffic patterns that might indicate exploitation attempts, such as unexpected file transfers or unusual protocol usage. Organizations should also consider implementing network access control lists and intrusion detection systems to identify and block malicious traffic targeting known vulnerabilities in network infrastructure devices. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter and T1071 for application layer protocol, highlighting the need for comprehensive network monitoring and endpoint protection measures to detect and prevent exploitation attempts.