CVE-2017-7946 in radare2
Summary
by MITRE
The get_relocs_64 function in libr/bin/format/mach0/mach0.c in radare2 1.3.0 allows remote attackers to cause a denial of service (use-after-free and application crash) via a crafted Mach0 file.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7946 resides within the radare2 reverse engineering framework, specifically in the Mach0 file format parser component. This flaw manifests in the get_relocs_64 function located in libr/bin/format/mach0/mach0.c at version 1.3.0, where improper memory management leads to a use-after-free condition that can be exploited remotely. The issue occurs when radare2 processes maliciously crafted Mach0 binaries, which are commonly used as executables on macOS and iOS systems. The vulnerability represents a critical security flaw that undermines the integrity and availability of the analysis environment, as it allows remote attackers to trigger application crashes and potentially disrupt legitimate analysis workflows.
The technical root cause of this vulnerability stems from improper handling of memory allocations within the Mach0 parsing logic. When the get_relocs_64 function processes relocation entries in a malformed Mach0 file, it fails to properly validate the structure and bounds of the relocation data before attempting to access memory locations that may have already been freed or reallocated. This use-after-free condition creates a scenario where subsequent memory operations reference deallocated memory blocks, leading to unpredictable behavior including application crashes, memory corruption, or potential privilege escalation. The flaw aligns with CWE-416, which specifically addresses use-after-free vulnerabilities in software implementations, and demonstrates how improper memory lifecycle management can create exploitable conditions in binary analysis tools.
The operational impact of this vulnerability extends beyond simple denial of service, as it can severely disrupt security research and reverse engineering activities that depend on radare2 for malware analysis, software debugging, and system security assessments. Attackers can leverage this vulnerability by crafting specially designed Mach0 files that, when opened by radare2, trigger the use-after-free condition and cause the application to crash. This creates a significant risk for security professionals who rely on radare2 for their work, as adversaries could potentially deliver malicious binaries that compromise the analysis environment. The vulnerability also has implications for automated analysis systems that might process untrusted binaries, as it could be exploited to cause service interruptions in security toolchains. From an ATT&CK framework perspective, this vulnerability maps to the T1059.007 technique related to execution through command and scripting interpreter, as it can be used to disrupt analyst workflows and potentially allow for more sophisticated attacks through service disruption.
Mitigation strategies for CVE-2017-7946 should prioritize immediate patching of affected radare2 installations to version 1.3.1 or later, which contains the necessary memory management fixes. Organizations should implement defensive measures such as restricting access to untrusted binary files and employing sandboxing techniques when processing potentially malicious executables. Security teams should also consider implementing network-based detection mechanisms to identify attempts to exploit this vulnerability through crafted Mach0 files. Additionally, regular security assessments of reverse engineering tools and automated analysis systems can help identify similar memory safety issues that may exist in other components of the security toolchain. The vulnerability highlights the importance of robust memory management practices in security tools and underscores the need for comprehensive input validation and error handling in binary parsing libraries to prevent similar issues from arising in other software components.