Description
DrayTek Vigor310 devices through 4.3.2.6 allow a remote attacker to execute arbitrary code via the function ft_payload_dns(), because a byte sign-extension operation occurs for the length argument of a _memcpy call, leading to a heap-based Buffer Overflow.
EPSS Score:
1%
Comprehensive Technical Analysis of EUVD-2024-39090
1. Vulnerability Assessment and Severity Evaluation
The vulnerability described in EUVD-2024-39090 affects DrayTek Vigor310 devices up to version 4.3.2.6. The issue arises from a heap-based buffer overflow in the function ft_payload_dns(), caused by a byte sign-extension operation during a _memcpy call. This vulnerability allows a remote attacker to execute arbitrary code, leading to severe consequences.
Severity Evaluation:
- CVSS Base Score: 9.8 (Critical)
- CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The high CVSS score indicates that the vulnerability is critical. The attack vector (AV:N) is network-based, requiring no user interaction (UI:N) or privileges (PR:N). The complexity of the attack is low (AC:L), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H).
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Remote Code Execution (RCE): An attacker can exploit the buffer overflow to execute arbitrary code on the affected device.
- Denial of Service (DoS): The buffer overflow can also be used to crash the device, leading to a denial of service.
Exploitation Methods:
- Crafted DNS Payload: An attacker can send a specially crafted DNS payload to the vulnerable device, triggering the buffer overflow in the
ft_payload_dns()function. - Network-Based Attack: Given the network-based attack vector, the attacker can exploit the vulnerability over the internet or local network without needing physical access to the device.
3. Affected Systems and Software Versions
Affected Systems:
- DrayTek Vigor310 devices
Affected Software Versions:
- All versions up to and including 4.3.2.6
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Patching: Apply the latest firmware update provided by DrayTek to mitigate the vulnerability.
- Network Segmentation: Isolate affected devices from the public internet and limit access to trusted networks.
- Firewall Rules: Implement strict firewall rules to block unsolicited incoming traffic to the affected devices.
Long-Term Mitigation:
- Regular Updates: Ensure that all network devices are regularly updated with the latest security patches.
- Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious network activity and potential exploitation attempts.
- Security Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate potential risks.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to European organizations and individuals using DrayTek Vigor310 devices. The potential for remote code execution and denial of service attacks can lead to data breaches, service disruptions, and financial losses. The widespread use of DrayTek devices in small to medium-sized businesses (SMBs) and home offices amplifies the impact, making it a critical concern for European cybersecurity.
6. Technical Details for Security Professionals
Vulnerability Details:
- Function Affected:
ft_payload_dns() - Issue: Byte sign-extension operation during a
_memcpycall leads to a heap-based buffer overflow. - Exploitation: The attacker can manipulate the length argument of the
_memcpycall to overwrite adjacent memory, leading to arbitrary code execution.
Detection and Response:
- Log Analysis: Monitor logs for unusual DNS traffic patterns and memory access violations.
- Memory Analysis: Use memory analysis tools to detect and investigate suspicious memory operations.
- Incident Response: Have an incident response plan in place to quickly identify, contain, and remediate any exploitation attempts.
References:
Conclusion: The vulnerability EUVD-2024-39090 is a critical issue affecting DrayTek Vigor310 devices. Immediate patching and implementation of mitigation strategies are essential to protect against potential exploitation. Organizations should prioritize updating their devices and enhancing their security posture to mitigate the risks associated with this vulnerability.