CVE-2024-27619: Buffer Overflow
Dlink Dir-3040us A1 1.20b03a hotfix is vulnerable to Buffer Overflow. Any user having read/write access to ftp server can write directly to ram causing buffer overflow if file or files uploaded are greater than available ram. Ftp server allows change of directory to root which is one level up than root of usb flash directory. During upload ram is getting filled and causing system resource exhaustion (no free memory) which causes system to crash and reboot.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Dlink Dir-3040usto a version that resolves this vulnerability.Fixed in 1.20b03aPatch hotfix - Compensating control
Ensure only trusted users have read/write access to the FTP server; prevent untrusted users from uploading files that could overflow memory (e.g., restrict FTP write permissions/access).
- Compensating control
Restrict FTP directory traversal/permissions so FTP users cannot change directory to locations above the intended root of the USB flash directory (disallow access to the root parent directory).
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker needs read/write access to the device's FTP server. The CVSS vector indicates this is exploitable from an adjacent network and requires low privileges, with no user interaction.
What conditions trigger the crash?
The issue is triggered by uploading files whose total size exceeds available RAM through the FTP server. During upload, RAM exhaustion can cause the device to crash and reboot.
Does access to the USB flash directory restrict the affected FTP uploads?
No. The FTP server allows changing directory to the system root, which is one level above the USB flash directory root, allowing uploads outside the expected USB flash directory scope.
What is the impact of successful exploitation?
Successful exploitation can exhaust system memory, causing a denial of service through a crash and reboot. The supplied CVSS vector also rates integrity and availability impact as high.