CVE-2019-9070 in binutils
Summary
by MITRE
An issue was discovered in GNU libiberty, as distributed in GNU Binutils 2.32. It is a heap-based buffer over-read in d_expression_1 in cp-demangle.c after many recursive calls.
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Analysis
by VulDB Data Team • 07/19/2023
The vulnerability identified as CVE-2019-9070 represents a critical heap-based buffer over-read condition within GNU libiberty, a core component of the GNU Binutils 2.32 package. This issue manifests specifically within the d_expression_1 function located in the cp-demangle.c file, which is responsible for demangling C++ symbols during binary processing operations. The flaw occurs when the demangler encounters highly recursive symbol structures, creating a scenario where memory access exceeds allocated buffer boundaries. This type of vulnerability falls under the category of memory safety issues that can potentially lead to arbitrary code execution or system instability.
The technical implementation of this vulnerability stems from inadequate bounds checking within the demangling algorithm's recursive processing logic. When the d_expression_1 function processes complex nested C++ expressions containing numerous recursive calls, it fails to properly validate memory access patterns against allocated buffer limits. This condition creates an over-read scenario where the function attempts to read memory locations beyond the intended buffer boundaries, potentially exposing sensitive data or allowing attackers to manipulate program execution flow. The vulnerability is particularly concerning because it occurs during symbol demangling operations that are commonly performed by various binary analysis tools and debuggers, making it exploitable in multiple attack vectors.
The operational impact of CVE-2019-9070 extends beyond simple memory corruption, as it can enable attackers to achieve arbitrary code execution within applications that utilize the vulnerable libiberty library. Systems using GNU Binutils 2.32 or affected versions are at risk when processing maliciously crafted binaries or when encountering complex symbol structures during debugging or analysis operations. The vulnerability can be exploited through various attack vectors including but not limited to malformed binary files, compromised development tools, or malicious software packages that trigger the demangling process. This makes the flaw particularly dangerous in environments where automated binary analysis or symbol resolution is performed, as these operations can be triggered without explicit user interaction.
Mitigation strategies for CVE-2019-9070 should prioritize immediate patching of affected GNU Binutils installations to version 2.33 or later, which contains the necessary fixes for the buffer over-read condition. Organizations should also implement additional defensive measures such as restricting access to binary analysis tools, implementing strict input validation for processed binaries, and monitoring for suspicious symbol structures that may indicate exploitation attempts. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and can be mapped to ATT&CK technique T1059.007 for execution through binary exploitation. Security teams should also consider implementing runtime protections such as address space layout randomization and stack canaries to reduce the effectiveness of potential exploitation attempts, while maintaining comprehensive logging of demangling operations for threat detection purposes.