CVE-2015-1593 in Android
Summary
by MITRE
The stack randomization feature in the Linux kernel before 3.19.1 on 64-bit platforms uses incorrect data types for the results of bitwise left-shift operations, which makes it easier for attackers to bypass the ASLR protection mechanism by predicting the address of the top of the stack, related to the randomize_stack_top function in fs/binfmt_elf.c and the stack_maxrandom_size function in arch/x86/mm/mmap.c.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability described in CVE-2015-1593 represents a critical flaw in the Linux kernel's address space layout randomization implementation specifically affecting 64-bit platforms. This weakness resides in the stack randomization mechanism that is fundamental to modern operating system security defenses against exploitation techniques. The issue manifests in the kernel versions prior to 3.19.1 where the randomization algorithm fails to properly handle data type conversions during bitwise left-shift operations, creating a predictable pattern that undermines the intended security benefits of ASLR.
The technical flaw occurs within the randomize_stack_top function located in fs/binfmt_elf.c and the stack_maxrandom_size function found in arch/x86/mm/mmap.c. These functions are responsible for generating random stack pointer values that should make it difficult for attackers to determine the memory layout of processes. However, due to incorrect data type handling during left-shift operations, the randomization process produces results that follow predictable patterns rather than true random distributions. This specific implementation error allows attackers to reverse engineer the randomization algorithm and calculate the likely location of the stack top, effectively nullifying the ASLR protection that is supposed to prevent memory corruption exploits.
The operational impact of this vulnerability is significant as it directly compromises one of the primary defenses against exploitation techniques such as return-oriented programming and stack-based buffer overflow attacks. When attackers can predict stack addresses, they gain substantial advantages in bypassing memory protection mechanisms that are designed to prevent code injection and arbitrary code execution. This vulnerability particularly affects systems running kernel versions before 3.19.1 on 64-bit architectures, making them susceptible to sophisticated attacks that rely on precise memory layout knowledge. The flaw essentially allows attackers to craft exploits that would otherwise be impossible to develop due to the unpredictability that ASLR normally provides.
The vulnerability aligns with CWE-697, which describes insufficient randomness in security-critical functions, and represents a direct violation of security principles that require robust entropy generation for memory layout randomization. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and defense evasion, as it enables attackers to bypass operating system security controls that are designed to prevent exploitation. The flaw demonstrates how subtle implementation errors in cryptographic or randomization functions can create severe security implications, as the mathematical operations that should provide entropy instead produce predictable outcomes. Organizations should prioritize updating their kernel versions to 3.19.1 or later to remediate this vulnerability, as the fix addresses the underlying data type conversion issues that were allowing attackers to predict stack locations and undermine the security benefits of ASLR.
This vulnerability highlights the critical importance of proper data type handling in security-sensitive code and demonstrates how seemingly minor implementation details can have major security consequences. The flaw serves as a reminder that even well-established security mechanisms can be compromised by subtle coding errors in low-level system components. System administrators should ensure that all 64-bit Linux systems are updated to kernel versions that contain the appropriate fixes, as the vulnerability remains exploitable in affected configurations and could enable sophisticated attacks against vulnerable systems.