CVE-2015-2846 in BitTorrent Sync
Summary
by MITRE
BitTorrent Sync allows remote attackers to execute arbitrary commands via a crafted btsync: link.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/22/2018
BitTorrent Sync is a peer-to-peer file synchronization tool that enables users to share files across devices without relying on centralized servers. The vulnerability described in CVE-2015-2846 represents a critical remote code execution flaw that exists within the application's handling of specially crafted btsync: protocol links. This vulnerability allows remote attackers to execute arbitrary commands on systems where BitTorrent Sync is installed, effectively bypassing normal security boundaries and potentially providing full system compromise capabilities.
The technical flaw manifests in the application's insufficient validation of URI parameters within btsync: links. When a user clicks on a maliciously crafted link, the application fails to properly sanitize input parameters before processing them, leading to command injection vulnerabilities. This weakness directly maps to CWE-77 which describes improper neutralization of special elements used in commands, and CWE-94 which addresses improper control of generation of code. The vulnerability exists because the BitTorrent Sync client does not adequately validate or escape parameters passed through the btsync: URI scheme, allowing attackers to inject malicious commands that get executed within the context of the running application.
The operational impact of this vulnerability is severe and multifaceted. An attacker can leverage this flaw to execute arbitrary code on vulnerable systems, potentially leading to complete system compromise, data exfiltration, or lateral movement within networks. The attack vector is particularly dangerous because it requires no special privileges or complex exploitation techniques beyond crafting a malicious link. This vulnerability affects all versions of BitTorrent Sync that process btsync: URIs without proper input sanitization, making it a widespread concern for organizations using the software. The vulnerability also aligns with ATT&CK technique T1059.007 which describes command and scripting interpreter for execution, and T1203 which covers exploitation for client execution.
Mitigation strategies for CVE-2015-2846 should include immediate patching of affected BitTorrent Sync installations to the latest version that addresses the input validation issues. Organizations should implement strict network controls to prevent users from accessing untrusted websites or downloading malicious links, particularly in enterprise environments where BitTorrent Sync might be used. Network segmentation and firewall rules can help limit the potential impact if an attacker successfully exploits the vulnerability. Additionally, user education regarding the dangers of clicking on unknown or suspicious links should be emphasized. Security monitoring should include detection of unusual command execution patterns and network traffic associated with btsync: protocol usage. The vulnerability also highlights the importance of proper input validation and parameter sanitization in all applications, particularly those that process user-provided data through URI schemes or similar mechanisms. Organizations should conduct regular security assessments of their file synchronization tools and ensure that proper security controls are in place to prevent similar vulnerabilities from occurring in other software components.