CVE-2025-20931 is a heap-based buffer overflow vulnerability classified under CWE-122, identified in Samsung Notes, a note-taking application pre-installed on many Samsung mobile devices. The vulnerability exists in the BMP image parsing functionality, where an out-of-bounds write occurs due to improper bounds checking when processing BMP files embedded or imported into notes. This flaw allows a local attacker—who has access to the device and can supply a malicious BMP file—to execute arbitrary code within the context of the Samsung Notes application. The vulnerability does not require any privileges or user interaction, making it easier to exploit if local access is obtained. The CVSS v3.1 base score is 7.3, reflecting a high severity with low attack complexity, no privileges required, and no user interaction needed. The impact includes partial confidentiality loss, high integrity compromise (due to arbitrary code execution), and limited availability impact. Although no exploits have been reported in the wild, the vulnerability poses a significant risk due to the widespread use of Samsung Notes on Samsung mobile devices. No official patch links are currently available, but updating to Samsung Notes version 4.4.26.71 or later is expected to remediate the issue. The vulnerability was reserved in November 2024 and published in March 2025.

The primary impact of CVE-2025-20931 is the potential for local attackers to execute arbitrary code on affected Samsung mobile devices, leading to a compromise of the integrity of the Samsung Notes application and potentially the device itself. This could allow attackers to manipulate or delete notes, inject malicious payloads, or escalate privileges if combined with other vulnerabilities. Confidentiality is partially impacted as attackers may access sensitive note content or data processed by the application. Availability impact is limited but could include application crashes or denial of service. Organizations relying on Samsung devices for sensitive communications or data storage may face increased risk of data breaches or unauthorized access. The vulnerability's ease of exploitation without user interaction or privileges heightens the threat, especially in environments where devices are shared or physically accessible by untrusted individuals. Although no known exploits exist yet, the vulnerability could be weaponized by attackers targeting Samsung mobile users, particularly in corporate or government sectors.

1. Immediately monitor for the release of Samsung Notes version 4.4.26.71 or later and apply the update as soon as it becomes available to remediate the vulnerability. 2. Restrict local access to Samsung devices by enforcing strong physical security controls and device lock policies to prevent unauthorized users from exploiting the vulnerability. 3. Implement mobile device management (MDM) solutions to enforce application updates and restrict installation of untrusted files, including BMP images from unknown sources. 4. Educate users about the risks of opening or importing untrusted image files into Samsung Notes or other applications. 5. Employ application whitelisting and sandboxing where possible to limit the impact of potential code execution within Samsung Notes. 6. Monitor device logs and behavior for signs of exploitation or abnormal activity related to Samsung Notes. 7. For high-security environments, consider restricting or disabling Samsung Notes usage until the patch is applied.