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In this blog post, we present a brief analysis of vulnerability CVE-2025-4802 [1], which affects libc developed by the GNU project, glibc, across versions 2.27 to 2.38, spanning the years 2017 to 2023 [2].
In simple terms, this vulnerability allows statically linked ELF binaries that execute dlopen() [3] either implicitly or explicitly to load arbitrary libraries via the LD_LIBRARY_PATH environment variable on a SUID binary. In practical terms, this enables a user with limited privileges to execute arbitrary code with elevated permissions.
Our objective is to provide the foundational knowledge required to understand the issue comprehensively. We will analyze the root cause of the vulnerability, the patch, its security impact, and how the involved components – the loader, the dynamic linker, and the kernel – interact to enable binary execution on the system. The operating system used for this blog post is Ubuntu 22.04, as provided to the students during our Linux binary exploitation training course.
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