CVE-2024-4464: Synology Media Server Auth Bypass Flaw

CVE-2024-4464 Overview

CVE-2024-4464 is an authorization bypass through user-controlled key vulnerability in the streaming service of Synology Media Server. The flaw allows remote, unauthenticated attackers to read specific files via unspecified network vectors. The vulnerability is classified under [CWE-639] Authorization Bypass Through User-Controlled Key, where the application relies on client-supplied identifiers to enforce access controls. Synology assigned the issue tracking number SA-24-28 and released fixed builds 1.4-2680, 2.0.5-3152, and 2.2.0-3325 for the affected Media Server package.

Critical Impact
Remote unauthenticated attackers can read specific files served by the Synology Media Server streaming component without user interaction.

Affected Products

Synology Media Server versions prior to 1.4-2680
Synology Media Server versions prior to 2.0.5-3152
Synology Media Server versions prior to 2.2.0-3325

Discovery Timeline

2024-12-18 - CVE-2024-4464 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-4464

Vulnerability Analysis

The vulnerability resides in the streaming service component of Synology Media Server. The service exposes endpoints that accept identifiers supplied by the requesting client to locate and stream media resources. Because the service trusts these client-controlled keys without verifying that the requesting principal is authorized to access the underlying resource, an attacker can manipulate the identifier to obtain content outside their intended scope.

Exploitation requires network access to the Media Server but does not require authentication, privileges, or user interaction. The impact is limited to confidentiality, allowing attackers to read specific files exposed by the streaming service. Integrity and availability are not affected. Refer to the Synology Security Advisory SA-24-28 for vendor-confirmed technical scope.

Root Cause

The root cause is missing authorization enforcement on a user-controlled key parameter. The streaming service uses the supplied key to resolve a resource path or identifier but does not validate that the caller has permission to read that resource. This pattern matches [CWE-639], where access control decisions depend on attacker-modifiable input.

Attack Vector

The attack vector is network-based with low complexity. An attacker reaches the Media Server streaming endpoint over HTTP and submits a crafted request containing a modified resource key. The server returns the targeted file content without performing an ownership or session check. Synology has not published the specific vector details, and no public proof-of-concept is currently available.

The vulnerability mechanism is described in prose only. No verified exploit code has been released, and synthetic exploitation samples are not included here. See the vendor advisory for remediation-relevant technical context.

Detection Methods for CVE-2024-4464

Indicators of Compromise

Unauthenticated HTTP requests to Synology Media Server streaming endpoints originating from external or unexpected source addresses.
Repeated requests to the streaming service with sequentially or programmatically varied resource identifiers.
Outbound transfers of media or document content from the DiskStation appliance to unknown remote hosts.

Detection Strategies

Inspect DSM and Media Server access logs for high volumes of streaming requests lacking valid session context.
Correlate Media Server request patterns against known-good client behavior to flag enumeration of resource identifiers.
Apply network monitoring rules that alert on access to Media Server ports from outside trusted network segments.

Monitoring Recommendations

Forward DSM logs to a centralized log platform and retain Media Server access entries for retrospective hunting.
Track the Media Server package version on each NAS and alert when it falls behind the fixed builds listed by Synology.
Monitor egress bandwidth from NAS appliances for anomalous spikes that may indicate bulk file exfiltration.

How to Mitigate CVE-2024-4464

Immediate Actions Required

Update Synology Media Server to version 1.4-2680, 2.0.5-3152, or 2.2.0-3325 or later, depending on the DSM release in use.
Restrict Media Server exposure to trusted local networks and remove any direct internet exposure through QuickConnect or port forwarding.
Audit DSM user accounts and shared folder permissions to ensure least-privilege access to media libraries.

Patch Information

Synology released fixed Media Server builds documented in Synology Security Advisory SA-24-28. Administrators should apply the package update through DSM Package Center or download the fixed package directly from the Synology Download Center. Verify the installed package version after upgrade to confirm remediation.

Workarounds

Disable the Media Server package on DiskStation devices where streaming functionality is not required until patches are applied.
Place the NAS behind a firewall or VPN and block external access to Media Server service ports.
Use DSM firewall rules to restrict Media Server access to specific client IP ranges within the local network.

bash

# Verify the installed Synology Media Server package version on DSM
synopkg version MediaServer

# Confirm the version is at or above the fixed builds:
#   1.4-2680, 2.0.5-3152, or 2.2.0-3325