CVE-2016-5035 in libdwarf
Summary
by MITRE
The _dwarf_read_line_table_header function in dwarf_line_table_reader.c in libdwarf before 20160923 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted file.
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Analysis
by VulDB Data Team • 08/15/2020
The vulnerability identified as CVE-2016-5035 resides within the libdwarf library, specifically in the _dwarf_read_line_table_header function located in dwarf_line_table_reader.c. This flaw represents a critical security issue that affects systems processing debug information files, particularly those utilizing DWARF (Debugging With Attributed Record Formats) debugging data structures. The vulnerability manifests as an out-of-bounds read condition that can be exploited by remote attackers through the careful crafting of malicious input files, potentially leading to system instability and denial of service scenarios.
The technical implementation of this vulnerability stems from insufficient input validation and boundary checking within the line table header parsing routine. When the _dwarf_read_line_table_header function processes malformed DWARF debug information files, it fails to properly validate array indices or buffer boundaries before accessing memory locations. This deficiency allows an attacker to construct a specially crafted debug file that, when processed by a vulnerable system, triggers memory access violations. The out-of-bounds read occurs because the function does not adequately verify that data pointers or array indices remain within acceptable limits, enabling arbitrary memory access patterns that can cause the application to crash or behave unpredictably.
From an operational perspective, this vulnerability presents significant risks to systems that process or analyze debug information files, particularly in development environments, continuous integration pipelines, and security analysis tools. The impact extends beyond simple denial of service as it can potentially be leveraged to execute arbitrary code or escalate privileges, depending on the specific implementation and system context. Systems that automatically process user-uploaded debug files, compile large codebases with extensive debugging information, or perform static analysis on binary files become particularly vulnerable to this attack vector. The remote exploitation capability means that attackers can trigger this vulnerability from external networks without requiring local system access, making it especially dangerous in multi-tenant environments or public-facing applications.
Mitigation strategies for CVE-2016-5035 should prioritize immediate patching of affected libdwarf versions to ensure that the library is updated to a release post-20160923 where the vulnerability has been addressed. Organizations should implement comprehensive input validation and sanitization procedures for any debug information processing components, particularly when handling externally sourced or untrusted files. Network segmentation and access controls should be enforced to limit exposure of systems that process debug data. The vulnerability aligns with CWE-129, which describes improper validation of array indices, and can be categorized under ATT&CK technique T1059 for execution through system commands and T1499 for denial of service. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other debugging and analysis libraries, as the underlying architectural issues may exist in related components. Additionally, implementing robust error handling and memory safety mechanisms in debug information processing applications can help prevent exploitation even if similar vulnerabilities are discovered in the future.