CVE-2019-14563 in EDK II
Summary
by MITRE • 11/23/2020
Integer truncation in EDK II may allow an authenticated user to potentially enable escalation of privilege via local access.
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Analysis
by VulDB Data Team • 05/21/2025
The vulnerability identified as CVE-2019-14563 resides within the EDK II (EFI Development Kit II) software development framework that serves as the foundation for creating UEFI firmware implementations across various hardware platforms. This critical security flaw manifests as an integer truncation issue that can be exploited by authenticated users with local access to potentially escalate their privileges within the system. The EDK II framework is widely utilized by major technology vendors including intel, amd, and various hardware manufacturers to develop firmware components that control the initial boot process and system-level operations. The vulnerability specifically affects the firmware build process where integer values are improperly handled during arithmetic operations, creating a potential pathway for privilege escalation attacks.
The technical nature of this vulnerability stems from improper integer handling within the firmware compilation and building processes of EDK II. When the build system processes certain integer values during firmware generation, it performs truncation operations that can result in unexpected behavior when dealing with large numerical values. This truncation occurs in contexts where signed and unsigned integer operations are mixed without proper validation, potentially causing the system to interpret certain values incorrectly. The flaw is particularly dangerous because it operates at the firmware level where privilege escalation can lead to complete system compromise, as firmware runs with the highest system privileges and can manipulate core system operations. This vulnerability is classified under CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic operations produce results that exceed the maximum value representable by the data type, leading to unpredictable behavior.
The operational impact of CVE-2019-14563 extends far beyond typical software vulnerabilities due to its position within the firmware development lifecycle. An authenticated user with local access to a system running EDK II can exploit this vulnerability to gain elevated privileges that would normally be restricted to system administrators or firmware developers. This privilege escalation can potentially allow attackers to modify firmware images, inject malicious code into the boot process, or manipulate system security settings that control access to critical hardware components. The vulnerability is particularly concerning in enterprise environments where firmware updates and system configurations are managed through EDK II frameworks, as it could enable attackers to establish persistent backdoors or compromise the integrity of the entire boot process. The attack vector requires local authentication but can be leveraged to gain root-level access to system firmware, making it a significant threat to system security and integrity.
Mitigation strategies for CVE-2019-14563 should focus on immediate patching of affected EDK II implementations and comprehensive code review processes to identify similar integer truncation vulnerabilities within the firmware development framework. Organizations should ensure they are running patched versions of EDK II that address the integer truncation issues, particularly those affecting the firmware build tools and compilation processes. Security teams should implement regular vulnerability assessments of their firmware development environments and conduct thorough code reviews focusing on integer handling operations and arithmetic calculations. The mitigation approach aligns with ATT&CK technique T1068, Exploitation for Privilege Escalation, as it involves exploiting weaknesses in system components to gain elevated privileges. Additionally, implementing proper input validation and integer overflow protection mechanisms within the EDK II build processes can prevent similar vulnerabilities from emerging in future versions. Organizations should also consider establishing secure firmware update procedures and maintaining detailed audit trails of firmware modifications to detect potential exploitation attempts.