CVE-2026-113678 in Froxlor
Summary
by MITRE • 10/20/2026
Froxlor before 2.3.15 contains a symlink following vulnerability in Statistics::makeChownWithNewStats that allows authenticated customers to take ownership of arbitrary host directories by abusing the root-run traffic cron. Attackers can replace the goaccess statistics directory in their document root with a symlink, causing chown -R to hand root-owned trees to them and enabling root escalation.
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Analysis
by VulDB Data Team • 10/20/2026
The vulnerability identified in Froxlor versions prior to 2.3.15 represents a critical privilege escalation flaw rooted in improper handling of symbolic links during file system operations. Specifically, the defect resides within the Statistics::makeChownWithNewStats function, which is invoked by a cron job that executes with root privileges. This architectural design choice creates an opportunity for authenticated users to manipulate the underlying file system structure to bypass intended access controls. The core technical flaw involves the lack of validation or restriction on symbolic links when the chown command is executed recursively. In standard Unix-like operating systems, if a directory contains symlinks pointing outside its own tree, and those targets are owned by root, executing chown -R on the parent directory can inadvertently transfer ownership of those external target directories to the user who invoked the operation or their associated process context, depending on how the command resolves paths.
In this specific scenario, an authenticated customer with access to manage their web document root is able to create a symbolic link within that directory structure. By pointing this symlink to arbitrary host directories owned by the root user, such as /etc/shadow or other sensitive system files and directories, the attacker sets a trap for the automated maintenance script. When the traffic statistics cron job runs, it triggers the makeChownWithNewStats function, which attempts to update ownership of files within the customer's document root using chown -R. Because the command does not check whether paths are symbolic links or resolve them safely before changing ownership, it follows the symlink and changes the owner of the target directory to that of the authenticated user. This effectively grants the low-privileged user administrative control over critical system resources.
The operational impact of this vulnerability is severe, as it allows for direct root escalation without requiring any additional exploits or privilege bypass techniques beyond initial authentication. Once an attacker gains ownership of sensitive directories or files, they can modify configuration files, inject malicious scripts into system paths, or alter permissions to allow further exploitation. This compromises the integrity and confidentiality of the entire hosting environment managed by Froxlor. Since the vulnerability relies on a cron job running as root, it is particularly dangerous because automated tasks often have broader access rights than interactive user sessions. The ability to take ownership of arbitrary host directories undermines the fundamental isolation between virtual hosts in a shared hosting or VPS management context, potentially leading to multi-tenant compromise where one customer can affect others or the underlying server infrastructure.
From a classification perspective, this vulnerability aligns with CWE-59: Improper Link Resolution Before File Access, commonly known as symlink following vulnerabilities. It also relates to CWE-264: Permissions and Privileges Issues due to the improper assignment of ownership rights that result in privilege escalation. In terms of attack vectors, this falls under MITRE ATT&CK technique T1059: Command and Scripting Interpreter if we consider the automated execution context, but more accurately it represents a local privilege escalation path often categorized under T1068: Exploitation for Privilege Escalation or specifically leveraging misconfigured file permissions. The attack requires authenticated access, placing it in the Initial Access phase of the kill chain before moving to Persistence and Privilege Escalation phases once the symlink is established and the cron job executes.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements. The primary remediation is to upgrade Froxlor to version 2.3.15 or later, where this specific logic flaw in the Statistics module has been addressed by developers who likely implemented checks to prevent following symlinks during ownership changes. In environments where upgrading is not immediately feasible, administrators should restrict the permissions of the cron job running as root if possible, although changing a system-level cron user often breaks functionality. A more robust defensive measure involves configuring the chown command or the underlying script to use options that do not follow symbolic links, such as ensuring the implementation uses lchown instead of chown for symlink targets, or explicitly checking file types before processing them. Additionally, enforcing strict directory permissions and monitoring for unusual ownership changes in system directories can help detect exploitation attempts early. Regular audits of cron job configurations and application code reviews focusing on file system operations are essential to prevent similar vulnerabilities from being introduced in future updates.