CVE-2017-6969 in binutils
Summary
by MITRE
readelf in GNU Binutils 2.28 is vulnerable to a heap-based buffer over-read while processing corrupt RL78 binaries. The vulnerability can trigger program crashes. It may lead to an information leak as well.
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Analysis
by VulDB Data Team • 09/09/2020
The vulnerability identified as CVE-2017-6969 affects readelf, a utility within GNU Binutils version 2.28, specifically when processing RL78 architecture binaries. This flaw represents a heap-based buffer over-read condition that occurs during the parsing of malformed or corrupted RL78 binary files. The issue stems from insufficient input validation and boundary checking within the readelf implementation, particularly in how it handles the processing of relocation entries specific to the RL78 architecture. The vulnerability manifests when the utility attempts to read data beyond the allocated heap buffer boundaries, creating a scenario where adjacent memory regions are accessed without proper authorization. This type of vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions that can result in information disclosure and system instability.
The technical exploitation of this vulnerability requires an attacker to craft or obtain a malformed RL78 binary file that triggers the buffer over-read condition within readelf. When the utility processes such a file, it attempts to parse relocation entries without adequate bounds checking, leading to memory access violations that cause program crashes. However, the more concerning aspect of this vulnerability is the potential for information leakage that may occur during the over-read operation. The heap-based nature of the flaw means that adjacent memory segments containing sensitive data may be inadvertently exposed to the attacker, potentially revealing stack contents, heap metadata, or other confidential information. This information disclosure capability significantly increases the attack surface and potential impact of the vulnerability, as it could expose system memory contents that might include cryptographic keys, user credentials, or other sensitive data.
From an operational perspective, this vulnerability presents a significant risk to systems that process or analyze binary files from untrusted sources. The impact extends beyond simple denial of service, as the information leakage aspect could compromise system security and confidentiality. Attackers could leverage this vulnerability to gather intelligence about system memory layout, potentially aiding in more sophisticated exploitation techniques. The vulnerability is particularly concerning in environments where automated binary analysis tools are employed, as these systems may be regularly processing files from diverse sources without proper sanitization. The RL78 architecture, being a 16-bit microcontroller architecture primarily used in automotive and embedded systems, makes this vulnerability relevant to industrial control systems and automotive security domains. The flaw's classification under the ATT&CK framework would fall under the T1059.007 technique for execution through command and scripting interpreter, specifically when attackers use automated binary analysis tools as part of their reconnaissance or exploitation activities.
Mitigation strategies for CVE-2017-6969 should focus on immediate patching of affected GNU Binutils installations to version 2.29 or later, which contains the necessary fixes for the buffer over-read condition. Organizations should also implement input validation and sanitization measures when processing binary files, particularly those from untrusted sources, to prevent exploitation of similar vulnerabilities. Additionally, system administrators should consider implementing sandboxing or containment measures for binary analysis utilities to limit the potential impact of successful exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of GNU Binutils, while monitoring for suspicious binary file processing activities that might indicate exploitation attempts. The remediation process should also include updating automated security tools and ensuring that binary analysis workflows do not inadvertently expose systems to this vulnerability through improper input handling or processing of malformed binary content.