CVE-2025-69647 in Binutils
Summary
by MITRE • 03/09/2026
GNU Binutils thru 2.45.1 readelf contains a denial-of-service vulnerability when processing a crafted binary with malformed DWARF loclists data. A logic flaw in the DWARF parsing code can cause readelf to repeatedly print the same table output without making forward progress, resulting in an unbounded output loop that never terminates unless externally interrupted. A local attacker can trigger this behavior by supplying a malicious input file, causing excessive CPU and I/O usage and preventing readelf from completing its analysis.
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Analysis
by VulDB Data Team • 03/12/2026
The vulnerability identified as CVE-2025-69647 affects GNU Binutils version 2.45.1 and earlier, specifically within the readelf utility that is part of the widely-used binutils package. This security flaw resides in the DWARF debugging information parsing functionality, which is essential for analyzing binary files and extracting debugging data. The issue manifests when readelf encounters malformed DWARF loclists data within a crafted binary file, creating a condition that fundamentally undermines the utility's normal operational behavior. The vulnerability represents a classic example of a logic flaw that can be exploited to cause denial-of-service conditions in security-critical tools used for binary analysis and reverse engineering.
The technical root cause of this vulnerability stems from a logic flaw in the DWARF parsing code that handles loclists data structures. When readelf processes a malformed DWARF loclists entry, the parsing routine enters an infinite loop where it repeatedly outputs identical table data without advancing through the file structure. This creates an unbounded output loop that consumes excessive CPU cycles and I/O resources, effectively rendering the readelf utility non-responsive. The flaw specifically affects the loclists parsing logic, which is responsible for processing location lists that describe where variables are stored in memory during program execution. This parsing routine fails to properly validate input data structures, allowing malformed entries to trigger the problematic behavior. The vulnerability operates at the parsing level, making it particularly dangerous as it can be triggered by simply providing a malicious input file to the readelf utility.
The operational impact of this vulnerability extends beyond simple resource exhaustion, as it affects the reliability and availability of security analysis tools that depend on readelf for binary inspection. A local attacker can exploit this weakness by preparing a malicious binary file containing crafted DWARF loclists data, then execute readelf against this file to initiate the denial-of-service condition. The consequences include sustained high CPU utilization, excessive memory consumption, and potential system resource exhaustion that can affect other processes running on the same system. This vulnerability is particularly concerning in environments where automated binary analysis is performed, as it can be exploited to disrupt security operations and prevent legitimate analysis tasks from completing. The lack of forward progress in the parsing routine means that even if an attacker has access to process interruption mechanisms, the utility will continue to consume resources until manually terminated, creating a persistent denial-of-service condition.
Security professionals should consider this vulnerability in the context of the Common Weakness Enumeration framework, where it aligns with CWE-835, which describes the weakness of a loop that does not make forward progress. The ATT&CK framework categorizes this as a resource exhaustion technique that can be used to disrupt system availability. The vulnerability's impact is significant because readelf is a fundamental tool used by developers, security analysts, and penetration testers for examining binary files and debugging information. Mitigation strategies should include immediate patching of GNU Binutils to version 2.45.2 or later, which contains the necessary fixes for the DWARF parsing logic. Additionally, organizations should implement input validation measures when processing unknown binary files, particularly in automated analysis environments where untrusted inputs are common. System administrators should monitor for unusual CPU and I/O usage patterns that might indicate exploitation attempts, and consider implementing sandboxing or restricted execution environments for binary analysis tools to prevent complete system disruption. The vulnerability also highlights the importance of robust input validation in security-critical utilities and demonstrates how seemingly minor parsing errors can have significant operational impacts on system availability.