CVE-2014-9934 in Android
Summary
by MITRE
A PKCS#1 v1.5 signature verification routine in all Android releases from CAF using the Linux kernel may not check padding.
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Analysis
by VulDB Data Team • 12/24/2020
The vulnerability identified as CVE-2014-9934 represents a critical flaw in the cryptographic signature verification process within Android operating systems. This issue affects all Android releases that utilize the Linux kernel and are developed by the Code Aurora Forum, which serves as a major upstream source for Android kernel components. The vulnerability specifically targets the PKCS#1 v1.5 signature verification implementation, which is a widely adopted standard for cryptographic signatures in various security protocols. The flaw lies in the insufficient validation of padding mechanisms during the signature verification process, potentially allowing attackers to bypass critical security checks that should validate the integrity and authenticity of digital signatures.
The technical root cause of this vulnerability stems from the improper implementation of PKCS#1 v1.5 padding verification within the kernel-level cryptographic routines. In standard PKCS#1 v1.5 signature verification, the padding must be carefully validated to ensure that the signature was generated using the correct key and that the data has not been tampered with during transmission. When padding validation is omitted or improperly implemented, it creates a window of opportunity for attackers to craft forged signatures that will pass the verification routine. This flaw falls under the category of improper input validation, which is classified as CWE-20 by the CWE standard, and specifically relates to cryptographic failures in signature verification processes. The vulnerability is particularly concerning because it operates at the kernel level where it can affect all cryptographic operations performed by the system.
The operational impact of CVE-2014-9934 extends far beyond simple cryptographic weakness, as it can enable attackers to perform various malicious activities including certificate forgery, authentication bypasses, and man-in-the-middle attacks. Mobile devices running affected Android versions become vulnerable to attacks that could compromise the entire security chain, particularly affecting applications that rely on cryptographic signatures for authentication or data integrity. The vulnerability affects a broad range of Android devices since it resides in the core kernel components that are shared across multiple device manufacturers and Android versions. This creates a widespread risk profile that impacts not only individual user devices but also enterprise security infrastructure that depends on Android-based platforms for mobile device management and security operations.
The attack surface for this vulnerability aligns with several techniques described in the MITRE ATT&CK framework, particularly those related to credential access and defense evasion. Attackers could leverage this weakness to perform certificate spoofing attacks, potentially gaining unauthorized access to secure applications or services that rely on digital signatures for authentication. The vulnerability also enables privilege escalation scenarios where attackers might manipulate signed system components to gain elevated privileges within the Android environment. Organizations should consider implementing mitigations such as kernel updates, signature verification hardening, and comprehensive security monitoring to detect potential exploitation attempts. Additionally, the vulnerability highlights the importance of proper cryptographic implementation practices and emphasizes the need for regular security assessments of kernel-level components that handle sensitive cryptographic operations. The flaw demonstrates the critical importance of adhering to established cryptographic standards and the potential consequences of incomplete implementation of well-defined security protocols.