CVE-2018-12178 in EDK II
Summary
by MITRE
Buffer overflow in network stack for EDK II may allow unprivileged user to potentially enable escalation of privilege and/or denial of service via network.
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Analysis
by VulDB Data Team • 08/08/2023
The vulnerability identified as CVE-2018-12178 represents a critical buffer overflow flaw within the network stack implementation of the EDK II firmware development environment. This issue resides in the UEFI network protocol handling mechanisms that are fundamental to system boot processes and network communication. The vulnerability affects systems that utilize EDK II as their firmware development framework, particularly those implementing UEFI network drivers that process incoming network packets. The buffer overflow occurs during the processing of network data structures where insufficient bounds checking allows maliciously crafted network traffic to overwrite adjacent memory regions. This flaw is particularly concerning because it operates at the firmware level where traditional operating system security controls may not be fully effective, creating a potential attack surface that spans from initial system boot through runtime network operations. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when a program writes beyond the boundaries of a fixed-length buffer, potentially corrupting adjacent memory locations and leading to arbitrary code execution or system instability. The network stack component in EDK II is responsible for handling various UEFI network protocols including IPv4 and IPv6 packet processing, DHCP operations, and other network communication functions that are essential for system initialization and runtime functionality.
The technical exploitation of this buffer overflow vulnerability requires an attacker to send specifically crafted network packets to a target system running firmware based on EDK II. The attack vector leverages the network interface to deliver malicious data that overflows buffer boundaries within the UEFI network stack implementation. Successful exploitation can lead to privilege escalation because the UEFI environment typically operates with elevated privileges compared to standard user applications, allowing attackers to potentially gain root-level access to the system firmware. The attack can also result in denial of service conditions where the buffer overflow corrupts critical system memory, causing system crashes, boot failures, or complete system lockups. The vulnerability's impact is amplified by the fact that UEFI firmware operates at a level below the operating system, making traditional security mechanisms like ASLR, DEP, and stack canaries less effective or completely bypassed. This allows attackers to execute code with the highest privilege level possible on the system, effectively compromising the entire platform security model. The attack requires minimal privileges from the attacker's perspective since the vulnerability exists within the network stack that is typically accessible from unprivileged network connections, making it particularly dangerous in environments where network exposure is common.
The operational impact of CVE-2018-12178 extends far beyond simple privilege escalation or denial of service scenarios, as it fundamentally undermines the security architecture of systems that rely on EDK II firmware implementations. Organizations using affected firmware may experience complete system compromise where attackers can establish persistent backdoors through firmware modifications, bypass traditional security controls, and maintain long-term access to affected systems. The vulnerability's presence in UEFI implementations means that even systems that have been patched at the operating system level remain at risk, as the exploit targets the firmware layer where such patches are not typically applied. This creates a significant challenge for security teams who must ensure that all firmware components, including those from EDK II, are properly updated and secured. The vulnerability can be particularly devastating in enterprise environments where UEFI-based systems are deployed across multiple platforms, potentially allowing attackers to compromise entire network infrastructures. The attack surface is further expanded by the fact that UEFI firmware is often updated through network-based mechanisms, creating potential for attacks during the update process itself. This vulnerability aligns with ATT&CK technique T1068 which describes the exploitation of vulnerabilities in operating systems or firmware to gain system-level privileges, and T1014 which covers the use of rootkits or bootkits to maintain persistence in the system. The impact is particularly severe in environments where UEFI-based systems are used for critical infrastructure, cloud computing platforms, or enterprise security systems where a compromised firmware can lead to widespread security breaches.
Mitigation strategies for CVE-2018-12178 must address both immediate remediation and long-term security posture improvements. The primary recommendation is to update all affected systems to versions of EDK II that contain patches for this buffer overflow vulnerability, with particular attention to firmware versions that have been specifically tested and validated for compatibility. Organizations should implement network segmentation and access controls to limit exposure of affected systems to untrusted network traffic, reducing the attack surface available to potential attackers. Network monitoring solutions should be deployed to detect and alert on suspicious network traffic patterns that may indicate exploitation attempts, particularly focusing on malformed packets that could trigger the buffer overflow conditions. System administrators should also consider implementing firmware integrity checking mechanisms and secure boot features that can detect and prevent unauthorized firmware modifications. Regular firmware audits and vulnerability assessments should be conducted to identify and remediate similar issues in other firmware components. The mitigation approach should also include updating network stack implementations to include proper bounds checking, input validation, and memory protection mechanisms. Organizations should establish firmware update policies that ensure timely patch deployment across all affected systems, particularly considering the critical nature of UEFI firmware in system security. Additionally, implementing network intrusion detection systems that can identify and block potentially malicious network traffic targeting UEFI network stack components provides an additional layer of defense against exploitation attempts. The vulnerability's classification under CWE-121 highlights the importance of implementing proper buffer management practices in firmware development, including the use of secure coding practices and thorough code reviews focused on memory handling and bounds checking mechanisms.