CVE-2016-5039 in libdwarf
Summary
by MITRE
The get_attr_value function in libdwarf before 20160923 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted object with all-bits on.
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Analysis
by VulDB Data Team • 08/15/2020
The vulnerability identified as CVE-2016-5039 affects the libdwarf library version prior to 20160923 and represents a critical out-of-bounds read flaw that can be exploited remotely. This issue manifests within the get_attr_value function, which is responsible for extracting attribute values from debug information structures. The vulnerability occurs when processing crafted object files that contain all-bits-on data patterns, creating a scenario where the function attempts to read memory beyond the allocated boundaries of the debug information structure.
The technical implementation of this vulnerability stems from insufficient bounds checking within the get_attr_value function. When libdwarf encounters debug information with malformed attribute data structures, particularly those containing all-bits-on patterns, the function fails to validate array indices or buffer limits before accessing memory locations. This flaw directly aligns with CWE-129, which describes improper validation of array indices, and CWE-131, which covers incorrect calculation of buffer size. The absence of proper input sanitization allows attackers to craft malicious object files that trigger memory access violations, resulting in unpredictable behavior including application crashes or system instability.
From an operational perspective, this vulnerability presents significant risks to systems that process or analyze debug information from untrusted sources. The remote exploitation capability means that attackers can potentially disrupt services by sending crafted object files to systems that utilize libdwarf for debugging, analysis, or reverse engineering purposes. The denial of service impact can affect various applications including compilers, debuggers, system analysis tools, and security scanners that rely on libdwarf functionality. This vulnerability particularly affects environments where automated processing of binary files occurs, such as software development pipelines, security analysis platforms, and forensic investigation tools.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1059, where adversaries leverage software flaws to cause system instability and disruption. Organizations using affected versions of libdwarf should prioritize immediate patching to mitigate this risk. The remediation strategy involves upgrading to libdwarf version 20160923 or later, which includes proper bounds checking and input validation mechanisms. Additional defensive measures should include implementing strict file validation for debug information processing, deploying intrusion detection systems to monitor for suspicious file patterns, and conducting regular security assessments of systems that utilize libdwarf functionality. Network segmentation and access controls can further limit the potential impact of successful exploitation attempts.