CVE-2024-0854 is an open redirect vulnerability identified in Synology DiskStation Manager (DSM), a widely used NAS (Network Attached Storage) operating system. This vulnerability exists in the file access component of DSM versions prior to 6.2.4-25556-8, 7.0.1-42218-7, 7.1.1-42962-7, and 7.2.1-69057-2. The flaw allows remote authenticated users to craft URLs that redirect unsuspecting users to untrusted external sites. Open redirect vulnerabilities occur when an application accepts a user-controlled input that specifies a link to an external site and redirects users to that site without sufficient validation. In this case, the vulnerability requires the attacker to have authenticated access to the DSM system, which limits exploitation to users with valid credentials or those who have compromised accounts. The attack vector involves phishing campaigns where attackers lure victims into clicking malicious links that appear to originate from a trusted Synology DSM instance but redirect to malicious websites. The vulnerability has a CVSS 3.1 base score of 5.4, indicating a medium severity level. The vector metrics indicate network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), scope changed (S:C), and impacts on confidentiality and integrity (C:L/I:L) but no impact on availability (A:N). There are no known exploits in the wild at the time of publication, and no official patches or mitigations have been linked yet. This vulnerability could be leveraged in targeted phishing attacks within organizations using Synology DSM, potentially leading to credential theft or further compromise through social engineering.

For European organizations, the impact of CVE-2024-0854 can be significant, especially for those relying on Synology DSM for critical file storage and sharing. The open redirect vulnerability can facilitate sophisticated phishing attacks that exploit user trust in internal systems, increasing the risk of credential compromise and unauthorized access. Since the vulnerability requires authenticated access, insider threats or compromised user accounts could be leveraged to launch attacks against other users or external targets. Confidentiality and integrity of data could be at risk if attackers use the redirect to harvest credentials or deliver malware payloads. Although availability is not directly impacted, the indirect consequences of successful phishing could lead to broader security incidents, including lateral movement within networks or data exfiltration. European organizations with remote or hybrid workforces may be particularly vulnerable due to increased reliance on web-based access to NAS devices. Additionally, regulatory frameworks such as GDPR impose strict requirements on data protection, and any compromise resulting from this vulnerability could lead to compliance issues and reputational damage.

To mitigate the risks posed by CVE-2024-0854, European organizations should implement the following specific measures: 1) Immediately verify and apply any available Synology DSM updates or patches that address this vulnerability once released. 2) Restrict DSM access to trusted networks and enforce strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of account compromise. 3) Conduct a thorough review of user privileges and remove or limit access for users who do not require DSM access, minimizing the attack surface. 4) Implement web filtering and email security solutions to detect and block phishing attempts that exploit this open redirect vulnerability. 5) Educate users about the risks of phishing and the importance of verifying URLs, especially when accessing DSM resources. 6) Monitor DSM logs for unusual redirect requests or suspicious user activity that could indicate exploitation attempts. 7) Consider deploying web application firewalls (WAF) or reverse proxies that can detect and block open redirect patterns. 8) If possible, configure DSM to validate or restrict redirect URLs to trusted domains only, reducing the likelihood of malicious redirection. These targeted actions go beyond generic advice and focus on reducing both the likelihood and impact of exploitation.