CVE-2016-5033 in libdwarf
Summary
by MITRE
The print_exprloc_content function 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-2016-5033 represents a critical out-of-bounds read flaw within the libdwarf library version prior to 20160923. This issue manifests specifically within the print_exprloc_content function, which is responsible for processing debug information expressed in DWARF format. The flaw occurs when the library processes malformed or crafted input files that contain invalid debug expressions, leading to memory access violations beyond the allocated buffer boundaries. Such vulnerabilities are particularly dangerous in debugging and analysis tools since they can be exploited by remote attackers who craft malicious files to be processed by vulnerable applications.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where programs access memory locations beyond the boundaries of allocated buffers. This flaw falls under the broader category of memory safety issues that have historically plagued software libraries handling complex data formats. The print_exprloc_content function fails to properly validate input boundaries when parsing debug expressions, allowing attackers to craft input that triggers memory access patterns beyond expected limits. This creates a scenario where the application reads memory locations that may contain sensitive data, uninitialized values, or even code segments that could be leveraged for more sophisticated attacks.
From an operational perspective, this vulnerability presents significant risk to systems that rely on libdwarf for processing debug information, particularly in development environments, debugging tools, and security analysis platforms. The remote attack vector means that adversaries can exploit this flaw without requiring local access to the target system, making it particularly dangerous in networked environments. When exploited, the out-of-bounds read can cause application crashes, leading to denial of service conditions that may disrupt legitimate user operations. Additionally, the vulnerability could potentially be leveraged as a stepping stone for more advanced attacks, as memory corruption issues often provide opportunities for information disclosure or code execution exploits.
The impact of CVE-2016-5033 extends beyond simple service disruption to potentially compromise system integrity and availability. Systems utilizing vulnerable versions of libdwarf include various debugging tools, security analysis frameworks, and development environments that process binary files with embedded debug information. The vulnerability is particularly concerning because it can be triggered through legitimate file processing operations, meaning that users may inadvertently trigger the exploit while performing routine tasks such as analyzing binaries or debugging applications. Organizations should prioritize patching affected systems, as the vulnerability affects widely used debugging and analysis libraries that form part of many software development and security toolchains.
Mitigation strategies for this vulnerability primarily involve updating to libdwarf version 20160923 or later, which contains the necessary fixes to properly validate input boundaries. System administrators should also implement input validation measures and consider sandboxing environments where debug information is processed. The ATT&CK framework categorizes such vulnerabilities under the 'Memory Corruption' technique, where adversaries leverage memory safety issues to disrupt system operations. Organizations should also consider implementing network segmentation and monitoring for unusual file processing activities that might indicate exploitation attempts. Regular security assessments of development and debugging toolchains are essential to identify and remediate similar vulnerabilities that may exist in other components of the software stack.