CVE-2025-5474 in SyncBackFree
Summary
by MITRE • 06/06/2025
2BrightSparks SyncBackFree Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of 2BrightSparks SyncBackFree. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. User interaction on the part of an administrator is also required.
The specific flaw exists within the Mirror functionality. By creating a junction, an attacker can abuse the service to delete arbitrary files. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-26962.
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Analysis
by VulDB Data Team • 08/18/2025
The CVE-2025-5474 vulnerability represents a critical local privilege escalation flaw in 2BrightSparks SyncBackFree software that demonstrates a significant weakness in the application's file system handling mechanisms. This vulnerability specifically targets the Mirror functionality component of the software, which is designed to synchronize files between different locations. The flaw allows attackers to exploit a path traversal vulnerability through junction manipulation that can lead to arbitrary file deletion and ultimately system compromise. The vulnerability is classified as a local privilege escalation issue that requires an attacker to first establish a foothold with low-privileged user access before leveraging this specific weakness to gain elevated privileges.
The technical implementation of this vulnerability stems from improper validation of file paths and directory structures within the Mirror feature of SyncBackFree. When an attacker creates a junction point that points to system directories or sensitive locations, the software's handling of these symbolic links allows for unintended file operations. This flaw specifically manifests when the application processes junctions in a manner that does not properly sanitize or validate the target paths, enabling attackers to manipulate the system's file structure. The vulnerability operates under the Common Weakness Enumeration (CWE) category of CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') and potentially CWE-73 - External Control of File Name or Path, which directly relates to the improper handling of file system references.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities. Once an attacker successfully exploits this vulnerability, they can execute arbitrary code with SYSTEM privileges, effectively taking complete control of the affected system. The requirement for administrator interaction suggests that while the initial exploitation might require user consent for certain operations, the underlying flaw allows for persistent access and control. This vulnerability creates a dangerous attack vector for adversaries who have already gained low-privileged access through other means, as it provides a reliable path to system-level compromise. The attack chain typically involves initial access through social engineering or other vector, followed by exploitation of this specific weakness to escalate privileges and maintain persistent access.
Mitigation strategies for CVE-2025-5474 should focus on immediate software updates from 2BrightSparks to address the underlying path traversal implementation flaws in the Mirror functionality. Organizations should implement strict access controls and user permission management to limit the ability of low-privileged users to manipulate file system junctions. The vulnerability's classification as a local privilege escalation issue means that network segmentation and principle of least privilege should be enforced to prevent lateral movement. Security teams should monitor for suspicious file deletion patterns and junction creation activities in system logs. Additionally, implementing application whitelisting policies and restricting the execution of unauthorized file system manipulation tools can help prevent exploitation. The ATT&CK framework categorizes this vulnerability under T1068 - Exploitation for Privilege Escalation, and T1547.001 - Registry Run Keys / Startup Folder, as the successful exploitation would likely result in persistence mechanisms being established. Organizations should also consider deploying endpoint detection and response solutions that can identify anomalous file system behavior indicative of junction manipulation attempts.