CVE-2017-9955 in binutils
Summary
by MITRE
The get_build_id function in opncls.c in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash) via a crafted file in which a certain size field is larger than a corresponding data field, as demonstrated by mishandling within the objdump program.
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Analysis
by VulDB Data Team • 12/05/2024
The vulnerability identified as CVE-2017-9955 resides within the Binary File Descriptor (BFD) library component of GNU Binutils version 2.28, specifically affecting the get_build_id function in the opncls.c file. This flaw represents a heap-based buffer over-read condition that can be exploited by remote attackers to induce denial of service through application crashes. The vulnerability manifests when processing crafted binary files where a size field exceeds the corresponding data field, creating a scenario where memory access operations extend beyond allocated buffer boundaries. The BFD library serves as a foundational component for various GNU tools including objdump, which is commonly used for examining binary files and displaying their contents in human-readable formats. When objdump encounters a malformed input file with inconsistent size and data field values, the get_build_id function fails to properly validate these parameters before attempting to read from memory locations beyond the intended buffer limits.
The technical execution of this vulnerability involves a classic buffer over-read attack pattern that operates on malformed data structures within binary file formats. The flaw stems from inadequate input validation mechanisms within the BFD library's handling of build identification metadata, where the size field is not properly constrained against the actual data payload. This condition creates an exploitable memory access pattern that allows attackers to manipulate the program flow by triggering memory reads from unauthorized locations. The vulnerability is particularly concerning because it affects a core library component that numerous security tools and system utilities depend upon, potentially enabling attackers to disrupt legitimate operations across multiple applications. The heap-based nature of the buffer over-read indicates that the memory corruption occurs within dynamically allocated heap segments rather than stack-based buffers, making the exploitation more complex but also more persistent in its effects.
The operational impact of CVE-2017-9955 extends beyond simple denial of service conditions to potentially compromise system availability and integrity. When exploited, this vulnerability can cause applications using the affected BFD library to crash unpredictably, leading to service disruption for legitimate users. The vulnerability's remote exploitation capability means that attackers can trigger the condition without requiring local access to the target system, making it particularly dangerous in networked environments where binary file analysis tools are frequently used. Security tools that rely on objdump and similar utilities for malware analysis, forensic investigations, or system diagnostics may become unavailable during exploitation attempts, creating cascading effects that impact broader security operations. The vulnerability also demonstrates a lack of proper bounds checking and input validation that violates fundamental security principles, potentially exposing systems to more sophisticated attacks if combined with other vulnerabilities.
Mitigation strategies for CVE-2017-9955 should prioritize immediate patching of affected GNU Binutils installations to version 2.29 or later where the vulnerability has been addressed through proper bounds checking and input validation mechanisms. Organizations should implement defensive programming practices including input sanitization and boundary validation for all binary file processing operations, particularly when dealing with untrusted input sources. The vulnerability aligns with CWE-129, which addresses improper validation of length fields, and represents a classic example of insufficient input validation that can lead to buffer over-read conditions. System administrators should also consider implementing network segmentation and access controls to limit exposure of systems running affected tools, while security monitoring should be enhanced to detect abnormal application crashes or memory access patterns. Additionally, organizations should conduct thorough vulnerability assessments to identify other potential instances of similar input validation issues within their software ecosystems, as this vulnerability demonstrates the importance of robust memory management practices in security-critical libraries. The ATT&CK framework categorizes this vulnerability under defensive evasion techniques, specifically targeting application security weaknesses that allow for service disruption and system compromise through memory corruption vulnerabilities.