CVE-2025-21039 is a medium-severity vulnerability affecting Samsung Mobile's S Assistant application, specifically in versions prior to 9.3.2. The issue stems from improper verification of intent by the SystemExceptionalBroadcastReceiver component within the app. Broadcast receivers in Android listen for system-wide or application-specific intents (messages) and act upon them. Improper verification means that the receiver does not adequately validate the source or content of the intent before processing it. This flaw allows a local attacker—someone with access to the device but without elevated privileges—to send crafted intents to the broadcast receiver. By exploiting this, the attacker can modify itinerary information managed by S Assistant. Itinerary data typically includes calendar events, travel plans, or reminders, which can be sensitive and integral to user scheduling. The CVSS v3.1 base score is 5.1, indicating a medium severity level. The vector string (AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L) shows that the attack requires local access (AV:L), low attack complexity (AC:L), no privileges (PR:N), no user interaction (UI:N), and impacts integrity and availability but not confidentiality. There are no known exploits in the wild at the time of publication, and no official patches have been linked yet. The vulnerability is categorized under CWE-925, which relates to improper verification of intent, a common issue in Android apps that can lead to privilege escalation or data manipulation if exploited.

For European organizations, the impact of this vulnerability depends largely on the use of Samsung mobile devices with the S Assistant app in their environment. Since the vulnerability allows local attackers to alter itinerary information, it could lead to misinformation or disruption in scheduling, potentially affecting operational efficiency. In sectors where precise scheduling is critical—such as logistics, transportation, or event management—this could cause operational delays or miscoordination. Although the confidentiality of data is not directly impacted, the integrity and availability of itinerary information are compromised, which could indirectly affect decision-making processes. Additionally, if attackers manipulate itinerary data to cause confusion or missed appointments, it could lead to reputational damage or financial loss. The requirement for local access limits remote exploitation, but insider threats or compromised devices could still pose risks. Given the widespread use of Samsung devices in Europe, especially in corporate and government sectors, the vulnerability could have a moderate operational impact if left unmitigated.

To mitigate this vulnerability, European organizations should: 1) Ensure all Samsung devices running S Assistant are updated to version 9.3.2 or later once patches are released by Samsung. 2) Restrict physical and local access to corporate mobile devices to prevent unauthorized local attackers from exploiting the flaw. 3) Implement Mobile Device Management (MDM) solutions to monitor and control app versions and enforce timely updates. 4) Educate users about the risks of installing untrusted apps or granting unnecessary permissions that could facilitate local exploitation. 5) Monitor device logs for unusual broadcast intents or modifications to itinerary data that could indicate exploitation attempts. 6) Consider disabling or limiting the use of S Assistant in high-security environments until the vulnerability is patched. 7) Collaborate with Samsung support channels to receive timely security advisories and patches.