CVE-2025-4802 is a high-severity vulnerability identified in the GNU C Library (glibc) versions 2.27 through 2.38. It stems from an untrusted search path issue related to the LD_LIBRARY_PATH environment variable. Specifically, this vulnerability affects statically compiled setuid binaries that invoke the dlopen function, either directly or indirectly (for example, through internal dlopen calls triggered by setlocale or Name Service Switch (NSS) functions such as getaddrinfo). The core problem is that these binaries can be tricked into loading attacker-controlled shared libraries due to improper validation of the LD_LIBRARY_PATH environment variable. This can lead to arbitrary code execution with elevated privileges since setuid binaries run with the privileges of the binary owner, often root. The vulnerability is classified under CWE-426 (Untrusted Search Path), highlighting the risk of loading malicious libraries from untrusted locations. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity but requiring user interaction and local access. No known exploits are currently reported in the wild, but the vulnerability's nature makes it a significant risk, especially on systems where setuid binaries are used for privileged operations and rely on glibc versions in the affected range. The absence of patch links suggests that remediation may require updates from the glibc maintainers or system vendors. This vulnerability underscores the importance of secure environment variable handling and cautious use of dynamic library loading in privileged contexts.

For European organizations, this vulnerability poses a serious threat, particularly to servers and critical infrastructure running Linux distributions that include affected glibc versions (2.27 to 2.38). Since glibc is a fundamental component of most Linux systems, the scope is broad. Exploitation could allow local attackers or malicious users with limited access to escalate privileges to root, compromising system confidentiality, integrity, and availability. This could lead to unauthorized data access, system manipulation, or denial of service. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are especially at risk due to the potential for severe operational disruption and data breaches. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk in environments where multiple users have shell or terminal access. Additionally, the use of setuid binaries in automated or multi-user environments increases exposure. The vulnerability could also be leveraged in targeted attacks or insider threat scenarios. Given the widespread use of glibc across European Linux distributions, the impact could be significant if not addressed promptly.

To mitigate CVE-2025-4802, European organizations should: 1) Immediately audit their systems to identify all statically compiled setuid binaries that call dlopen or related NSS functions. 2) Restrict or sanitize the LD_LIBRARY_PATH environment variable for all users, especially in contexts where setuid binaries are executed. This can be enforced by system-wide environment policies or by modifying shell profiles and service configurations to unset or ignore LD_LIBRARY_PATH. 3) Apply vendor or distribution patches as soon as they become available; monitor glibc updates from trusted sources. 4) Where possible, replace or recompile setuid binaries to avoid dynamic loading via dlopen or to use safer library loading practices. 5) Implement strict access controls and monitoring on systems with setuid binaries to detect suspicious activity related to environment variable manipulation or unexpected library loading. 6) Educate system administrators and users about the risks of environment variable manipulation and enforce the principle of least privilege to reduce the attack surface. 7) Consider deploying runtime application self-protection (RASP) or integrity monitoring tools that can detect unauthorized library loads or environment changes. These targeted measures go beyond generic patching and help reduce the risk of exploitation in complex environments.