CVE-2025-47153 in libuv
Summary
by MITRE • 05/01/2025
Certain build processes for libuv and Node.js for 32-bit systems, such as for the nodejs binary package through nodejs_20.19.0+dfsg-1_i386.deb for Debian GNU/Linux, have an inconsistent off_t size (e.g., building on i386 Debian always uses _FILE_OFFSET_BITS=64 for the libuv dynamic library, but uses the _FILE_OFFSET_BITS global system default of 32 for nodejs), leading to out-of-bounds access. NOTE: this is not a problem in the Node.js software itself. In particular, the Node.js website's download page does not offer prebuilt Node.js for Linux on i386.
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Analysis
by VulDB Data Team • 05/02/2025
This vulnerability manifests in the build process of libuv and Node.js specifically targeting 32-bit systems, creating a critical inconsistency in file offset handling that can lead to memory corruption. The issue occurs when building the nodejs binary package for Debian GNU/Linux systems, where the libuv dynamic library is compiled with _FILE_OFFSET_BITS=64 while the nodejs binary itself uses the system default of 32-bit file offsets. This fundamental mismatch creates a scenario where the application's memory management becomes inconsistent, potentially allowing attackers to manipulate file operations beyond their intended boundaries. The vulnerability is classified under CWE-129 as an insufficient input validation, specifically related to improper handling of file offset sizes in cross-compilation environments.
The technical flaw stems from the inconsistent application of the _FILE_OFFSET_BITS preprocessor directive during the build process, where libuv and nodejs components operate with different offset size expectations. When the libuv library is compiled with 64-bit file offset support, it expects larger file handle representations, while the nodejs binary continues to use 32-bit file offset semantics. This discrepancy becomes problematic during file operations that involve large file handling, where the application may attempt to access memory locations that are outside the bounds of allocated buffers or file handle structures. The vulnerability specifically affects 32-bit i386 architecture systems and occurs during the build phase rather than in runtime execution, making it a pre-compilation issue that can propagate into the final binary.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can enable attackers to manipulate file system operations in ways that may lead to privilege escalation or arbitrary code execution. The inconsistency in file offset handling creates potential for out-of-bounds memory access patterns that could be exploited through malicious file operations or by crafting specific inputs that trigger the vulnerable code paths. This issue particularly affects systems where nodejs is built from source on 32-bit platforms, as the build environment's configuration creates a mismatch that persists in the compiled binary. The vulnerability operates at the system level rather than the application level, making it difficult to detect through standard application security scanning tools.
Mitigation strategies for this vulnerability require addressing the build configuration inconsistency by ensuring that both libuv and nodejs components use identical _FILE_OFFSET_BITS settings during compilation. System administrators should avoid building nodejs from source on 32-bit systems unless absolutely necessary, and if building is required, the build environment must be carefully configured to maintain consistent file offset handling across all components. The recommended approach involves modifying the build scripts to explicitly set _FILE_OFFSET_BITS=64 for both libraries and applications, ensuring that all components operate with the same file offset semantics. Additionally, organizations should consider migrating away from 32-bit i386 systems where possible, as this architecture presents inherent limitations in handling large file operations and increases vulnerability surface area. This vulnerability aligns with ATT&CK technique T1059.007 for execution through command and scripting interpreter, particularly when considering that attackers may exploit the memory corruption to execute arbitrary code through compromised file operations. The issue also relates to T1552.001 for credentials in files, as file system operations may be manipulated to access sensitive data through the memory corruption vectors. Organizations should implement strict build environment controls and maintain updated system configurations to prevent this inconsistency from occurring in production deployments.