CVE-2026-54575 in mport
Summary
by MITRE • 09/17/2026
mport is the MidnightBSD Package Manager. Prior to 2.7.8, privileged package fetch and cache-cleaning operations used race-prone path handling across libmport/fetch.c, libmport/clean.c, libmport/util.c, libmport/bundle_read_install_pkg.c, libmport/delete_primative.c, and libexec/mport.create/mport.create.c. A local attacker with write access to a participating package cache or staging path could race path checks and replacement operations to redirect package downloads, cleanup, or install-related side effects outside the intended cache. The affected lifecycle helper paths also used shell-form invocation, increasing command-line interpretation risk during privileged helper execution. This issue is fixed in version 2.7.8.
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Analysis
by VulDB Data Team • 09/17/2026
The MidnightBSD Package Manager, known as mport, contains a critical security vulnerability affecting versions prior to 2.7.8 that stems from improper handling of file paths during privileged operations. The core technical flaw involves race conditions within the path validation logic used for package fetching and cache cleaning tasks. Specifically, files such as libmport/fetch.c, libmport/clean.c, libmport/util.c, libmport/bundle_read_install_pkg.c, libmport/delete_primative.c, and libexec/mport.create/mport.create.c fail to atomically verify the integrity of file paths before performing operations on them. This design oversight allows a local attacker who possesses write access to any participating package cache or staging directory to exploit the time-of-check-to-time-of-use gap. By rapidly manipulating files in these directories, an attacker can redirect package downloads, cleanup processes, or installation side effects away from their intended locations and into arbitrary paths controlled by the attacker. This capability effectively bypasses security boundaries that rely on path validation, enabling unauthorized modification of system state through privilege escalation mechanisms inherent to the package manager's helper execution model.
The operational impact of this vulnerability is significant because it allows a low-privileged user with write access to cache directories to influence high-privilege operations executed by root or other elevated accounts. An attacker could potentially inject malicious packages, corrupt legitimate software repositories, or execute arbitrary code during the installation process if the redirected paths lead to executable scripts or libraries that are subsequently loaded by the privileged helper processes. The risk is further exacerbated by the use of shell-form invocation for lifecycle helpers within these components. Shell interpretation introduces additional attack surfaces related command-line parsing and environment variable injection, which can be leveraged in conjunction with the path race condition to achieve more complex exploitation scenarios. This combination of a race condition and unsafe execution methods significantly lowers the barrier for local privilege escalation or system compromise on affected MidnightBSD systems.
From an industry standards perspective, this vulnerability aligns closely with CWE-367, which describes Time-of-check Time-of-use (TOCTOU) Race Conditions in file operations. The failure to ensure atomicity between checking a path's validity and using it for sensitive operations is the defining characteristic of this flaw. Additionally, the exploitation vector relates to ATT&CK technique T1059, Command and Scripting Interpreter, due to the shell-form invocation that increases the risk of command injection or unintended script execution during privileged helper runs. The vulnerability also touches upon CWE-267, Privilege Confusion When Maintaining Capabilities, as it involves manipulating paths within contexts where elevated privileges are active but not properly isolated from user-controlled inputs.
To mitigate this vulnerability, system administrators and developers must upgrade mport to version 2.7.8 or later immediately. This release addresses the race conditions by implementing robust path handling mechanisms that ensure atomicity during file operations. Developers should also review any custom scripts or configurations relying on shell-form invocation for privileged tasks and migrate them to direct binary execution where possible, thereby reducing the attack surface associated with command-line interpretation. Furthermore, restricting write access to package cache directories to only trusted system processes can provide an additional layer of defense against local attackers attempting to exploit these race conditions until a full patch is deployed across all affected systems.