CVE-2016-5034 in libdwarf
Summary
by MITRE
dwarf_elf_access.c in libdwarf before 20160923 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted file, related to relocation records.
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Analysis
by VulDB Data Team • 08/15/2020
The vulnerability identified as CVE-2016-5034 resides within the libdwarf library, specifically in the dwarf_elf_access.c component, affecting versions prior to 20160923. This flaw represents a critical security issue that enables remote attackers to execute denial of service attacks through carefully crafted input files. The vulnerability manifests as an out-of-bounds write condition that occurs during the processing of relocation records within elf files, making it particularly dangerous in environments where untrusted binary data is processed. The libdwarf library serves as a crucial component for parsing and accessing debug information in elf binaries, commonly used in system administration, security analysis, and software development tools. When an attacker crafts a malicious file containing malformed relocation records, the library fails to properly validate input boundaries, leading to memory corruption that can result in application crashes or system instability. This vulnerability directly maps to CWE-787: Out-of-bounds Write, which is classified as a severe weakness in the Common Weakness Enumeration catalog, representing a fundamental flaw in input validation and memory management. The attack surface for this vulnerability is broad as it affects any system or application that relies on libdwarf for processing elf files, including but not limited to debuggers, system analyzers, and security scanning tools. The operational impact extends beyond simple denial of service, as the out-of-bounds write can potentially lead to more severe consequences including arbitrary code execution depending on the specific implementation context and memory layout. In enterprise environments where automated security scanning or system monitoring tools process unknown binary files, this vulnerability poses a significant risk of system-wide disruption. The ATT&CK framework categorizes this vulnerability under T1499.004: Endpoint Denial of Service, as it targets system resources through manipulation of input data. The vulnerability is particularly concerning because it does not require privileged access or specific user interaction to exploit, making it a preferred target for automated attack vectors. Security researchers have noted that the flaw occurs during the normal processing flow of elf file analysis, meaning that legitimate applications using libdwarf could be affected simply by encountering a maliciously crafted file in their processing path. Remediation efforts must focus on updating to libdwarf version 20160923 or later, which includes proper input validation and boundary checks for relocation record processing. Additionally, system administrators should implement input sanitization measures and consider deploying intrusion detection systems that can identify potential exploitation attempts targeting this specific vulnerability. The fix implemented in the updated version addresses the root cause by introducing comprehensive validation of relocation record boundaries, preventing the out-of-bounds memory access that previously led to the denial of service condition. Organizations should also conduct vulnerability assessments to identify systems running vulnerable versions of libdwarf and prioritize patching based on risk exposure and system criticality.