Description
A vulnerability, which was classified as critical, has been found in D-Link DIR-632 FW103B08. Affected by this issue is the function get_pure_content of the component HTTP POST Request Handler. The manipulation of the argument Content-Length leads to stack-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2025-18394
1. Vulnerability Assessment and Severity Evaluation
The vulnerability EUVD-2025-18394, also known as CVE-2025-6121, is classified as critical with a CVSS base score of 9.3. This high score is attributed to several factors:
- Attack Vector (AV:N): The vulnerability can be exploited remotely over the network.
- Attack Complexity (AC:L): The attack requires low complexity, meaning it is relatively easy to exploit.
- Privileges Required (PR:N): No special privileges are required to exploit this vulnerability.
- User Interaction (UI:N): No user interaction is required for the exploit to be successful.
- Impact Metrics: The vulnerability has high impact on confidentiality (VC:H), integrity (VI:H), and availability (VA:H).
The vulnerability involves a stack-based buffer overflow in the get_pure_content function of the HTTP POST Request Handler component. This can lead to arbitrary code execution, making it a severe threat.
2. Potential Attack Vectors and Exploitation Methods
The primary attack vector is through manipulation of the Content-Length argument in HTTP POST requests. An attacker can send a specially crafted request with a malicious Content-Length value, causing a buffer overflow. This can result in:
- Arbitrary Code Execution: The attacker can execute arbitrary code on the affected device.
- Denial of Service (DoS): The device may crash or become unresponsive.
- Data Exfiltration: Sensitive information may be leaked or manipulated.
Exploitation methods include:
- Remote Code Execution (RCE): By sending a crafted HTTP POST request, an attacker can execute malicious code.
- DoS Attacks: Sending a large number of malformed requests can crash the device.
- Data Manipulation: An attacker can alter the data being processed by the device.
3. Affected Systems and Software Versions
The vulnerability specifically affects the D-Link DIR-632 router with firmware version FW103B08. It is important to note that this firmware version is no longer supported by the manufacturer, which means no patches or updates will be provided to mitigate this vulnerability.
4. Recommended Mitigation Strategies
Given that the affected firmware is no longer supported, the following mitigation strategies are recommended:
- Upgrade to Supported Firmware: If possible, upgrade to a supported firmware version that is not affected by this vulnerability.
- Network Segmentation: Isolate the affected device from critical networks to limit potential damage.
- Firewall Rules: Implement strict firewall rules to block unauthorized access to the device.
- Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious activity and potential exploitation attempts.
- Regular Audits: Conduct regular security audits to identify and mitigate similar vulnerabilities.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to European cybersecurity, particularly for organizations and individuals using the affected D-Link DIR-632 router. The potential for remote exploitation and the lack of vendor support exacerbate the risk. This underscores the importance of timely updates and the need for robust cybersecurity measures to protect against unsupported devices.
6. Technical Details for Security Professionals
- Vulnerable Function:
get_pure_contentin the HTTP POST Request Handler. - Exploit Mechanism: Manipulation of the
Content-Lengthargument in HTTP POST requests. - Public Exploit Availability: The exploit has been disclosed to the public and may be used by attackers.
- References:
Conclusion
EUVD-2025-18394 represents a critical vulnerability in the D-Link DIR-632 router, which can be exploited remotely with low complexity. Organizations and individuals using this device should take immediate action to mitigate the risk, including upgrading to supported firmware, implementing network segmentation, and deploying robust security measures. The European cybersecurity landscape must address the challenges posed by unsupported devices to ensure comprehensive protection against such vulnerabilities.