CVE-2024-12756 is a high-severity HTML Injection vulnerability identified in Avaya Spaces, a cloud-based collaboration and communication platform. The vulnerability is classified under CWE-1287, which relates to improper neutralization of HTML elements in a web page, allowing an attacker to inject arbitrary HTML code into the content rendered to users. This flaw can lead to the disclosure of sensitive information or unauthorized modification of the page content as seen by the user. The CVSS 3.1 base score is 7.3, indicating a high impact, with the vector AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:N. This means the attack can be launched remotely over the network but requires high attack complexity, privileges, and user interaction. The scope is changed, indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality and integrity is high, while availability is not affected. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk because it can be leveraged to manipulate user views and potentially exfiltrate sensitive data or conduct phishing attacks within the trusted environment of Avaya Spaces. The affected versions are not explicitly detailed beyond "0," suggesting either an early or unspecified version. No patches or mitigations have been linked yet, emphasizing the need for vigilance and proactive defense by users of Avaya Spaces.

For European organizations using Avaya Spaces, this vulnerability could have serious consequences. Avaya Spaces is often used for internal communications, meetings, and collaboration, meaning that exploitation could lead to unauthorized disclosure of confidential corporate information or manipulation of communication content, undermining trust and operational integrity. Given the high confidentiality and integrity impact, attackers could impersonate trusted users or inject misleading information, potentially disrupting decision-making processes or leaking sensitive data subject to GDPR regulations. The requirement for user interaction and privileges limits the attack surface but does not eliminate risk, especially in large organizations where insider threats or phishing attacks could facilitate exploitation. The scope change indicates that the vulnerability could affect multiple components or users beyond the initially compromised element, increasing potential damage. The absence of known exploits in the wild provides a window for mitigation but also calls for immediate attention to prevent future exploitation. Overall, the threat could lead to regulatory penalties, reputational damage, and operational disruptions for European enterprises relying on Avaya Spaces for secure communication.

1. Immediate monitoring of Avaya Spaces usage for unusual HTML content or unexpected page modifications is recommended to detect potential exploitation attempts. 2. Restrict privileges and enforce the principle of least privilege to minimize the number of users who can perform actions requiring high privileges, reducing the attack surface. 3. Educate users about the risks of interacting with suspicious content within Avaya Spaces, emphasizing caution with unexpected prompts or links. 4. Implement Content Security Policy (CSP) headers if possible within the Avaya Spaces environment to restrict the execution of injected scripts or HTML elements. 5. Coordinate with Avaya support or security teams to obtain patches or updates as soon as they become available and apply them promptly. 6. Consider deploying web application firewalls (WAF) with custom rules to detect and block HTML injection patterns targeting Avaya Spaces endpoints. 7. Conduct regular security assessments and penetration testing focused on collaboration platforms to identify and remediate similar vulnerabilities proactively.