CVE-2017-9949 in radare2
Summary
by MITRE
The grub_memmove function in shlr/grub/kern/misc.c in radare2 1.5.0 allows remote attackers to cause a denial of service (stack-based buffer underflow and application crash) or possibly have unspecified other impact via a crafted binary file, possibly related to a buffer underflow in fs/ext2.c in GNU GRUB 2.02.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2017-9949 resides within the radare2 binary analysis framework version 1.5.0 and specifically targets the grub_memmove function located in shlr/grub/kern/misc.c. This flaw represents a critical stack-based buffer underflow condition that can be exploited by remote attackers through the careful crafting of malicious binary files. The vulnerability originates from a deeper issue within GNU GRUB 2.02's fs/ext2.c component, creating a cascading effect that propagates through the radare2 codebase. The underlying mechanism involves improper memory handling during buffer operations, where the grub_memmove function fails to properly validate buffer boundaries before performing memory movement operations.
The technical exploitation of this vulnerability occurs when radare2 processes a specially crafted binary file that triggers the buffer underflow condition in the grub_memmove function. This flaw operates at the kernel level of the GRUB bootloader implementation within radare2's shlr module, making it particularly dangerous as it can affect the fundamental binary analysis capabilities of the tool. The buffer underflow creates a condition where memory adjacent to the allocated buffer is overwritten or accessed, leading to unpredictable behavior and system instability. According to CWE standards, this vulnerability maps to CWE-121 Stack-based Buffer Overflow, which is classified as a critical weakness in memory safety. The attack surface is expanded through the ATT&CK framework's software exploitation techniques, specifically targeting the execution of arbitrary code through memory corruption vulnerabilities.
The operational impact of CVE-2017-9949 extends beyond simple denial of service conditions, as it can potentially lead to complete application crashes and system instability during binary analysis operations. When an attacker successfully exploits this vulnerability, they can cause radare2 to terminate unexpectedly, resulting in loss of analysis data and potentially exposing the analyst to further security risks. The vulnerability's potential for unspecified other impacts suggests that in certain conditions, attackers might be able to achieve more sophisticated exploitation techniques beyond simple denial of service. The stack-based nature of the buffer underflow means that the corruption can affect critical program execution flow, potentially allowing for privilege escalation or information disclosure scenarios.
Mitigation strategies for this vulnerability require immediate patching of radare2 to version 1.5.1 or later, which contains the necessary fixes for the grub_memmove function and related buffer handling code. System administrators and security professionals should also implement strict file validation procedures before processing binary files with radare2, particularly when analyzing files from untrusted sources. The implementation of memory safety checks and bounds verification within the affected code paths should be enforced through static analysis tools and runtime protections. Additionally, network segmentation and access controls should be implemented to limit exposure to potential attackers who might attempt to exploit this vulnerability through remote file processing. Organizations should also consider implementing automated monitoring for application crashes or unexpected termination patterns that might indicate exploitation attempts. The vulnerability's classification under CWE-121 and its exploitation patterns align with ATT&CK techniques for memory corruption attacks, making defensive measures more predictable and actionable for security teams implementing comprehensive threat mitigation strategies.