CVE-2017-1000366 in C Library
Summary
by MITRE
glibc contains a vulnerability that allows specially crafted LD_LIBRARY_PATH values to manipulate the heap/stack, causing them to alias, potentially resulting in arbitrary code execution. Please note that additional hardening changes have been made to glibc to prevent manipulation of stack and heap memory but these issues are not directly exploitable, as such they have not been given a CVE. This affects glibc 2.25 and earlier.
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Analysis
by VulDB Data Team • 01/11/2025
The vulnerability identified as CVE-2017-1000366 represents a critical heap corruption issue within the GNU C Library that enables attackers to manipulate memory layout through crafted LD_LIBRARY_PATH environment variables. This flaw exists in glibc versions 2.25 and earlier, where the dynamic loader fails to properly validate library paths during runtime loading, creating opportunities for memory aliasing between heap and stack regions. The vulnerability stems from improper handling of library search paths that can be manipulated to influence the memory allocation behavior of the runtime linker.
The technical implementation of this vulnerability exploits the way glibc processes LD_LIBRARY_PATH by allowing attackers to inject malicious library paths that cause the loader to map libraries at predictable memory addresses. When the dynamic linker resolves symbols and loads libraries, it can be tricked into placing heap-allocated memory in locations that overlap with stack memory regions. This memory aliasing creates a condition where modifications to one memory region can inadvertently affect the other, potentially leading to control flow hijacking. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though it manifests through heap manipulation rather than traditional stack corruption techniques.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with a sophisticated means of bypassing modern memory protection mechanisms. While the glibc maintainers implemented additional hardening measures to prevent direct stack and heap manipulation, the underlying issue remains exploitable through careful crafting of environment variables and library dependencies. Attackers can leverage this vulnerability to achieve arbitrary code execution by manipulating the memory layout to place shellcode or malicious function pointers in locations where they can be executed. The attack vector is particularly concerning because it can be triggered through standard library loading mechanisms without requiring direct user interaction or elevated privileges.
Mitigation strategies for CVE-2017-1000366 focus primarily on updating to glibc versions 2.26 or later where the vulnerability has been addressed through enhanced validation of library paths and improved memory layout management. System administrators should also implement environment variable restrictions to limit the influence of LD_LIBRARY_PATH, particularly in applications running with elevated privileges. Additional protective measures include enabling address space layout randomization ASLR, disabling unnecessary library loading paths, and implementing strict library dependency checks through security tools such as LD_DEBUG or custom auditing mechanisms. Organizations should also consider implementing runtime monitoring to detect anomalous library loading patterns that may indicate exploitation attempts, as this vulnerability operates through legitimate library loading mechanisms that are difficult to distinguish from normal application behavior. The ATT&CK framework categorizes this as a privilege escalation technique through library load manipulation, making it particularly relevant for enterprise security monitoring and incident response procedures.