CVE-2017-9052 in libdwarf
Summary
by MITRE
An issue, also known as DW201703-006, was discovered in libdwarf 2017-03-21. A heap-based buffer over-read in dwarf_formsdata() is due to a failure to check a pointer for being in bounds (in a few places in this function) and a failure in a check in dwarf_attr_list().
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Analysis
by VulDB Data Team • 12/25/2020
The vulnerability identified as CVE-2017-9052 represents a critical heap-based buffer over-read flaw within the libdwarf library version dated 2017-03-21. This issue manifests in the dwarf_formsdata() function where inadequate pointer bounds checking creates opportunities for malicious actors to exploit memory access violations. The vulnerability stems from multiple locations within the function where pointer validation is insufficient, combined with a flawed check mechanism in dwarf_attr_list() that fails to properly validate memory boundaries. Such oversights in memory management create conditions where attackers can potentially read data from memory locations beyond the intended buffer boundaries, leading to information disclosure and potential system compromise. The flaw specifically affects software systems that rely on libdwarf for processing dwarf debugging information, which is commonly used in development tools, debuggers, and system analysis utilities.
The technical implementation of this vulnerability occurs when the dwarf_formsdata() function processes debugging information without proper validation of pointer boundaries, particularly in scenarios where the library handles malformed or crafted dwarf data structures. The absence of comprehensive bounds checking in multiple code paths within this function creates multiple attack vectors that could be exploited through carefully constructed input data. Additionally, the insufficient validation in dwarf_attr_list() compounds the issue by failing to properly verify memory access patterns during attribute list processing. This combination of memory access violations creates a condition where arbitrary memory contents can be read beyond the intended buffer limits, potentially exposing sensitive data including stack contents, heap data, or other debugging information that should remain protected. The vulnerability aligns with CWE-125, which specifically addresses out-of-bounds read conditions, and represents a classic example of improper input validation in memory management operations.
The operational impact of CVE-2017-9052 extends beyond simple information disclosure to potentially enable more sophisticated attacks depending on the system context and the nature of the debugging data being processed. Systems that process untrusted dwarf debugging information, such as debuggers, system analyzers, or development environments, become vulnerable to exploitation when they utilize the affected libdwarf library version. Attackers could leverage this vulnerability to extract sensitive information from memory, potentially including cryptographic keys, passwords, or other confidential data that might be stored in adjacent memory regions. The vulnerability is particularly concerning in environments where debugging information is processed from untrusted sources, such as third-party libraries or user-provided binaries, as these scenarios provide ideal conditions for exploitation. The flaw's presence in a widely-used library means that numerous applications and tools could be affected, creating a broad attack surface that extends across multiple software ecosystems.
Mitigation strategies for CVE-2017-9052 focus primarily on updating to patched versions of the libdwarf library where the buffer over-read conditions have been addressed through proper pointer validation and bounds checking mechanisms. System administrators and developers should prioritize upgrading to libdwarf versions that include fixes for the specific memory access violations in dwarf_formsdata() and dwarf_attr_list() functions. Additionally, input validation measures should be implemented at application layers that process dwarf debugging information to reduce the attack surface. The implementation of address sanitizers and memory debugging tools during development can help identify similar issues in other library components. Organizations should also consider implementing runtime protections such as stack canaries and memory protection mechanisms to detect and prevent exploitation attempts. From an ATT&CK framework perspective, this vulnerability relates to techniques involving memory corruption and information disclosure, and defensive measures should include process isolation and input sanitization to reduce the potential impact of such exploits. Regular security audits and dependency monitoring are essential to identify and remediate similar vulnerabilities in other system components that may be susceptible to similar memory access violations.