CVE-2025-5702 is a medium-severity vulnerability identified in the GNU C Library (glibc) version 2.39 and later, specifically affecting the strcmp function implementation optimized for the IBM Power10 processor architecture. The flaw arises because the strcmp function writes to vector registers v20 to v31 without preserving their original contents. According to the powerpc64le ABI (Application Binary Interface), these registers are designated as non-volatile, meaning that their contents must be preserved across function calls. The failure to save and restore these registers leads to unintended overwriting of data held by the caller, which can result in altered control flow or leakage of sensitive input string data to other parts of the program. This vulnerability is classified under CWE-665 (Improper Initialization), indicating a failure to properly handle register state. The CVSS v3.1 base score is 5.6, reflecting a medium severity level, with the vector indicating network attack vector (AV:N), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), and low impacts on confidentiality, integrity, and availability (C:L/I:L/A:L). No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability is specific to Power10 processors running glibc 2.39+, which narrows the affected environment to systems using this architecture and glibc version. The issue could potentially be exploited remotely if an attacker can cause strcmp to be invoked with crafted inputs, but the high attack complexity and lack of privilege requirements suggest exploitation is non-trivial but possible in some scenarios. The impact includes potential leakage of sensitive data and subtle control flow corruption, which could facilitate further exploitation or information disclosure within affected applications.

For European organizations, the impact of CVE-2025-5702 depends largely on their deployment of Power10-based systems running glibc 2.39 or later. Power10 processors are primarily used in high-performance computing, enterprise servers, and specialized workloads, often in sectors such as finance, research, and government. Organizations relying on IBM Power10 infrastructure for critical applications may face risks of data leakage or integrity compromise due to this vulnerability. Although the direct impact is medium severity, the subtle corruption of non-volatile registers could lead to unpredictable application behavior or security bypasses in sensitive environments. This could affect confidentiality if input strings contain sensitive information, and integrity if control flow is altered. Availability impact is low but cannot be ruled out if corrupted state leads to crashes. Given the niche architecture, the threat is less widespread than vulnerabilities affecting x86_64 systems, but for affected organizations, the risk is material. The lack of known exploits reduces immediate risk, but the presence of a vulnerability in a core library like glibc means that any vulnerable software linked against it could be indirectly impacted. European organizations in sectors with high reliance on IBM Power10 servers, such as financial institutions, research labs, and government agencies, should prioritize assessment and mitigation.

1. Immediate mitigation involves auditing all systems running on Power10 processors to identify those with glibc version 2.39 or later. 2. Since no official patches are linked yet, organizations should monitor glibc project updates and apply patches promptly once released. 3. As a temporary workaround, consider recompiling glibc or affected applications with compiler flags or patches that disable the Power10-specific strcmp optimization, reverting to a safe implementation. 4. Implement runtime monitoring to detect anomalous behavior or crashes related to strcmp usage, especially in critical applications. 5. Restrict network exposure of vulnerable systems to reduce attack surface, employing strict firewall rules and network segmentation. 6. Conduct code reviews and testing for applications that heavily rely on strcmp to identify potential exploitation vectors or data leakage. 7. Engage with vendors and IBM support to understand timelines for official fixes and recommended mitigations. 8. Incorporate this vulnerability into incident response plans, preparing for potential exploitation scenarios. These steps go beyond generic advice by focusing on architecture-specific mitigations, proactive monitoring, and vendor engagement.