CVE-2025-53787 is a command injection vulnerability classified under CWE-77 affecting Microsoft 365 Copilot's Business Chat feature. The flaw arises from improper neutralization of special elements in user-supplied input, allowing attackers to inject and execute arbitrary commands on the underlying system. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The CVSS 3.1 base score is 8.2, reflecting a high severity due to the ease of exploitation (network vector, low attack complexity) and the significant confidentiality impact, as attackers can potentially access sensitive business chat data. Integrity impact is rated low since the attacker can modify some data or commands but not fully compromise system integrity. Availability is unaffected. The vulnerability was reserved on July 9, 2025, and published on August 7, 2025. No patches or known exploits are currently reported, but the lack of authentication and user interaction requirements makes this a critical issue for organizations using Microsoft 365 Copilot's Business Chat. The vulnerability could be exploited to disclose sensitive information or execute unauthorized commands, potentially leading to lateral movement or further compromise within enterprise environments.

For European organizations, the impact of CVE-2025-53787 is significant due to the widespread adoption of Microsoft 365 services in the region. The vulnerability could lead to unauthorized disclosure of sensitive business communications and data, undermining confidentiality and potentially violating GDPR requirements. The ability to execute commands remotely without authentication increases the risk of attackers gaining footholds in corporate networks, leading to further exploitation or data exfiltration. This is particularly critical for sectors such as finance, healthcare, and government agencies, where sensitive information is routinely handled. The integrity of business processes could be partially compromised, affecting trust in automated workflows and decision-making supported by Copilot's AI features. Although availability is not directly impacted, the indirect consequences of data breaches and command execution could disrupt business operations and damage organizational reputation.

1. Monitor Microsoft security advisories closely and apply official patches or updates for Microsoft 365 Copilot's Business Chat as soon as they become available. 2. Implement network segmentation and restrict access to Microsoft 365 Copilot services to trusted IP ranges and VPNs to reduce exposure. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious command injection patterns targeting Business Chat endpoints. 4. Enable and review detailed logging and alerting on Microsoft 365 Copilot usage to identify anomalous commands or data access. 5. Conduct regular security assessments and penetration tests focusing on integration points of AI-driven chat features. 6. Educate employees about the risks of interacting with AI chatbots and encourage reporting of unusual system behavior. 7. Use Microsoft Defender for Endpoint and other EDR solutions to detect and respond to potential exploitation attempts. 8. Limit permissions and roles within Microsoft 365 to the minimum necessary to reduce potential damage from compromised accounts or services.