CVE-2025-5278 in Coreutils
Summary
by MITRE • 05/28/2025
A flaw was found in GNU Coreutils. The sort utility's begfield() function is vulnerable to a heap buffer under-read. The program may access memory outside the allocated buffer if a user runs a crafted command using the traditional key format. A malicious input could lead to a crash or leak sensitive data.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability identified as CVE-2025-5278 resides within GNU Coreutils, specifically affecting the sort utility's begfield() function which is responsible for processing field-based sorting operations. This heap buffer under-read represents a critical memory safety issue that can be exploited through crafted command inputs utilizing the traditional key format. The flaw manifests when the sort utility processes user-supplied data that contains malformed field specifications, causing the underlying memory access to extend beyond the boundaries of allocated heap buffers. Such behavior fundamentally violates memory management principles and creates potential attack vectors that could be leveraged by adversaries to compromise system integrity.
The technical implementation of this vulnerability stems from inadequate bounds checking within the begfield() function's memory access patterns. When processing traditional key format specifications, the function fails to properly validate the boundaries of buffer allocations, allowing for under-read conditions that can access uninitialized memory regions or memory belonging to other program components. This type of memory corruption vulnerability aligns with CWE-125, which specifically addresses out-of-bounds read conditions, and represents a classic example of heap-based buffer over-read vulnerabilities. The attack surface is particularly concerning as it involves core system utilities that are frequently executed by both regular users and system processes, making exploitation potentially widespread and persistent across different environments.
The operational impact of this vulnerability extends beyond simple program crashes to include potential data leakage and system instability. When the under-read condition occurs, the program may inadvertently expose sensitive information stored in adjacent memory locations, potentially including authentication credentials, system configuration data, or other confidential information. Additionally, the memory corruption can cause unpredictable program behavior, leading to segmentation faults, application crashes, or in more severe cases, system instability that could affect overall system availability. The vulnerability's exploitation requires a specific input format that utilizes the traditional key format, but this constraint does not significantly limit the attack scope given that sort utilities are commonly used in automated scripts and system operations.
Mitigation strategies for CVE-2025-5278 should prioritize immediate patch application from trusted sources, as the vulnerability affects core system utilities that are fundamental to Unix-like operating systems. System administrators should implement input validation measures for all sort utility invocations, particularly in environments where untrusted input is processed. The ATT&CK framework's T1059.007 technique for command and scripting interpreter execution can be monitored to detect potential exploitation attempts through crafted sort commands. Additional defensive measures include implementing sandboxing for sort utility operations, deploying memory protection mechanisms such as stack canaries or address space layout randomization, and establishing monitoring protocols to detect anomalous memory access patterns that might indicate exploitation attempts. Organizations should also consider implementing least privilege principles for sort utility execution and regularly audit system configurations to ensure that vulnerable versions are not present in production environments.