CVE-2024-6381 is a vulnerability identified in the MongoDB C driver library libbson, specifically within the bson_strfreev function. This function is responsible for freeing an array of strings, and the vulnerability arises due to an integer overflow condition. When the function processes input, an integer overflow can occur, causing it to calculate a negative offset for memory freeing operations. This leads to a buffer overflow scenario where memory outside the intended bounds is freed, resulting in memory corruption. Such corruption can cause application crashes, undefined behavior, or potentially be exploited to execute arbitrary code, although no public exploits are known at this time. The vulnerability affects all libbson versions prior to 1.26.2, which was released to address this issue. The CVSS v3.1 score is 4.0 (medium), reflecting that exploitation requires local access (AV:L), no privileges (PR:N), no user interaction (UI:N), and impacts integrity but not confidentiality or availability. The scope is unchanged, meaning the vulnerability affects only the vulnerable component without extending to other system components. This vulnerability is classified under CWE-680 (Integer Overflow to Buffer Overflow), a common software weakness where improper handling of integer arithmetic leads to memory safety issues. Since libbson is widely used as a BSON manipulation library in MongoDB C drivers and related applications, any software relying on these libraries is potentially at risk if running vulnerable versions. The issue is particularly relevant for applications that handle BSON data locally and use the vulnerable function to free string arrays. No patches or exploit code are currently publicly available, but the vendor has released version 1.26.2 to fix the problem. Organizations should review their use of libbson and update accordingly to prevent potential exploitation.

The primary impact of CVE-2024-6381 is memory corruption due to a buffer overflow triggered by an integer overflow in the libbson library. For European organizations, this can lead to application instability, crashes, or potential escalation to arbitrary code execution if exploited in a targeted manner. Although exploitation requires local access, this can be a concern in environments where untrusted users or processes have local system access, such as shared development machines, CI/CD pipelines, or containerized environments. The integrity of applications processing BSON data could be compromised, potentially affecting data processing workflows or embedded systems using MongoDB C drivers. While confidentiality and availability impacts are rated as none, integrity degradation can still disrupt business operations or lead to further compromise if chained with other vulnerabilities. European sectors with heavy reliance on MongoDB for data storage or embedded applications—such as finance, telecommunications, and manufacturing—may face operational risks if vulnerable versions are not updated. The absence of known exploits reduces immediate risk, but the vulnerability's presence in foundational libraries means that attackers could develop exploits in the future, especially in targeted attacks against high-value assets.

1. Immediately upgrade libbson to version 1.26.2 or later, which contains the fix for this vulnerability. 2. Audit all applications and services using the MongoDB C driver or libbson to identify usage of the bson_strfreev function or related string freeing operations. 3. Restrict local access to systems running vulnerable versions to trusted users only, minimizing the risk of local exploitation. 4. Implement memory safety and integrity monitoring tools to detect abnormal memory operations or crashes that could indicate exploitation attempts. 5. Incorporate static and dynamic code analysis in development pipelines to detect unsafe integer operations and buffer handling issues in custom code interfacing with libbson. 6. For containerized or virtualized environments, ensure base images are updated to include patched libbson versions. 7. Monitor vendor advisories and security bulletins for any emerging exploit code or additional patches related to this vulnerability. 8. Educate developers and system administrators about the risks of integer overflows leading to buffer overflows and encourage secure coding practices.