CVE-2026-52533 in DIR-1253
Summary
by MITRE • 07/14/2026
An issue in D-Link DIR-1253 v.1.0.1.250923.142435 allows an attacker to escalate privileges via the etc/shadow component file
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Analysis
by VulDB Data Team • 07/14/2026
The vulnerability present in D-Link DIR-1253 firmware version 1.0.1.250923.142435 represents a critical privilege escalation flaw that stems from inadequate access controls within the device's file system management. This issue specifically targets the etc/shadow component file, which serves as a crucial security element storing encrypted user passwords and account information on Unix-like systems. The vulnerability manifests when an attacker can manipulate or directly access this sensitive file without proper authentication mechanisms, allowing them to elevate their privileges from standard user level to administrative access.
The technical root cause of this flaw lies in the firmware's insufficient input validation and authorization checks during file operations within the etc directory structure. This weakness creates an exploitable condition where malicious actors can bypass normal authentication procedures and gain unauthorized access to system-level resources. The etc/shadow file, which typically requires root privileges to modify, becomes accessible through improper privilege management within the router's web interface or command execution mechanisms. This vulnerability directly maps to CWE-269 Improper Privilege Management, as the device fails to properly enforce access controls for critical system files.
The operational impact of this privilege escalation vulnerability extends far beyond simple unauthorized access, creating a comprehensive security breach that allows attackers to fully compromise the network device. Once escalated, an attacker can modify system configurations, install malicious software, monitor network traffic, and potentially use the compromised router as a pivot point for attacking other devices within the local network. The vulnerability enables attacks that align with ATT&CK technique T1068 Privilege Escalation, specifically targeting the exploitation of weak file permissions and system-level access controls. Network administrators lose visibility into their protected infrastructure as the attacker can manipulate logs and system parameters to cover their tracks.
Mitigation strategies for this vulnerability require immediate firmware updates from D-Link to address the privilege management flaws in the affected firmware version. Organizations should implement network segmentation to limit lateral movement even if individual devices are compromised, and deploy intrusion detection systems to monitor for unauthorized file access attempts. Regular security audits of network device configurations should include verification of proper file permissions and access controls, particularly focusing on system-critical files within etc directories. Additionally, implementing multi-factor authentication mechanisms and regular password rotation policies can help reduce the attack surface while waiting for official patches to be released and deployed across affected networks.