CVE-2016-5042 in libdwarf
Summary
by MITRE
The dwarf_get_aranges_list function in libdwarf before 20160923 allows remote attackers to cause a denial of service (infinite loop and crash) via a crafted DWARF section.
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Analysis
by VulDB Data Team • 10/15/2019
The vulnerability identified as CVE-2016-5042 affects the libdwarf library version prior to 20160923, specifically within the dwarf_get_aranges_list function. This flaw represents a critical security issue that can be exploited by remote attackers to trigger denial of service conditions through carefully crafted DWARF debugging information sections. The affected library is widely used in software development tools, debuggers, and binary analysis utilities across various operating systems and platforms. The vulnerability stems from insufficient input validation and boundary checking within the DWARF section parsing logic, creating a scenario where malformed debugging data can cause the application to enter an infinite loop or crash entirely.
The technical implementation of this vulnerability involves the improper handling of DWARF debugging information structures, particularly when processing address range lists that are part of the DWARF standard. When the dwarf_get_aranges_list function encounters malformed or maliciously constructed DWARF sections containing invalid address range entries, the parsing algorithm fails to properly validate loop termination conditions. This leads to a condition where the function enters an infinite loop while attempting to process the corrupted data structure, consuming excessive CPU resources and potentially causing system instability. The vulnerability is classified under CWE-835, which specifically addresses the issue of infinite loops in software implementations, making it a direct descendant of the well-known weakness in loop control mechanisms.
From an operational impact perspective, this vulnerability poses significant risks to systems that rely on libdwarf for processing binary files, especially in development environments, security analysis tools, and automated build systems. Attackers can exploit this weakness by embedding malicious DWARF sections within legitimate binaries or by providing crafted input files to applications that utilize libdwarf for debugging information parsing. The attack surface extends to any software that processes DWARF debugging data, including compilers, debuggers, binary analyzers, and security scanning tools. The denial of service condition can result in complete system unresponsiveness, application crashes, or resource exhaustion that affects overall system availability and performance.
The mitigation strategy for CVE-2016-5042 primarily involves upgrading to libdwarf version 20160923 or later, which includes proper input validation and boundary checking mechanisms. System administrators should prioritize patching affected applications and development tools that depend on libdwarf, particularly those used in production environments or security-sensitive contexts. Additional defensive measures include implementing input sanitization for DWARF data processing, deploying network segmentation to limit exposure, and monitoring for unusual CPU consumption patterns that may indicate exploitation attempts. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how malformed data can be used to compromise system stability and availability in software systems that do not properly validate their inputs. Organizations should also consider implementing automated vulnerability scanning tools that can detect and alert on the presence of vulnerable libdwarf versions in their software supply chains.