CVE-2026-48097 Overview
CVE-2026-48097 is a command execution vulnerability in NexTor IP Changer, a command-line tool that rotates a user's IP address through the Tor network. Versions prior to 2.0.0 invoke subprocesses with shell=True while relying on the PATH environment variable to resolve executables such as sudo. An attacker who controls the execution environment can prepend a malicious binary directory to PATH, causing the tool to run attacker-controlled code with the invoking user's privileges. The issue is tracked under [CWE-78] (OS Command Injection) and is fixed in version 2.0.0.
Critical Impact
Local attackers who influence PATH can execute arbitrary code and escalate to whatever privileges NexTor invokes, including sudo contexts.
Affected Products
- NexTor IP Changer versions prior to 2.0.0
- Distributions and forks bundling the vulnerable script
- Environments where untrusted users can influence the PATH variable of the NexTor process
Discovery Timeline
- 2026-08-07 - CVE-2026-48097 published to NVD
- 2026-08-07 - Last updated in NVD database
Technical Details for CVE-2026-48097
Vulnerability Analysis
NexTor IP Changer spawns subprocesses using Python's subprocess module with shell=True. The commands issued (for example sudo used to restart the Tor service) are referenced by name rather than by absolute path. When shell=True is set, the shell resolves each command through the PATH environment variable in order. If an attacker can prepend a directory they control to PATH, the shell selects the attacker's binary instead of the legitimate system utility.
The primary abuse target is sudo. Because NexTor invokes sudo to control privileged operations, a shadowed sudo binary executes with whatever privileges the user grants it, including capturing credentials passed to the fake prompt. This maps to [CWE-78] and represents a Local Code Execution flaw with high impact to confidentiality, integrity, and availability.
Root Cause
The root cause is the combination of shell=True with unqualified executable names. Safe subprocess invocation requires either passing an argument list without shell=True or referencing binaries by absolute path (for example /usr/bin/sudo). The vulnerable versions do neither, delegating resolution to the current shell environment.
Attack Vector
Exploitation requires local access with the ability to influence the environment that launches NexTor. A common scenario involves a lower-privileged account writing a malicious sudo executable to a user-writable directory, then setting PATH so that directory precedes /usr/bin. Running NexTor then triggers execution of the malicious binary. See the GitHub Security Advisory GHSA-vx6r-vwjq-567w for the upstream description.
No public exploit code is referenced in the advisory. The vulnerability is described in prose in the upstream security advisory.
Detection Methods for CVE-2026-48097
Indicators of Compromise
- Presence of executables named sudo, tor, or systemctl in user-writable directories that appear earlier in PATH than /usr/bin or /usr/sbin.
- Unexpected child processes spawned by the NexTor Python interpreter that do not originate from standard system paths.
- Modifications to shell initialization files (.bashrc, .profile, .zshrc) that prepend user-controlled directories to PATH before running NexTor.
Detection Strategies
- Audit process execution telemetry for python or python3 processes launching binaries from non-standard directories such as /tmp, /home/*/bin, or /dev/shm.
- Alert on invocations of sudo whose executable path resolves outside /usr/bin/sudo or /bin/sudo.
- Search source trees and installed packages for subprocess calls that combine shell=True with unqualified command names.
Monitoring Recommendations
- Monitor changes to PATH in interactive shells and service unit files that host NexTor.
- Log and review new executables created in user home directories, especially those matching the names of privileged system utilities.
- Correlate NexTor process starts with subsequent privilege-relevant syscalls or authentication events.
How to Mitigate CVE-2026-48097
Immediate Actions Required
- Upgrade NexTor IP Changer to version 2.0.0 or later, available at the GitHub Release v2.0.
- Inventory hosts running NexTor and restrict execution to trusted administrators.
- Verify that no shadowing binaries exist earlier in PATH than the system directories on affected systems.
Patch Information
Version 2.0.0 resolves the issue by removing the unsafe shell=True pattern and referencing executables through explicit paths. Users of any version prior to 2.0.0 should upgrade. Details are documented in the GitHub Security Advisory GHSA-vx6r-vwjq-567w.
Workarounds
- Run NexTor with a sanitized PATH that lists only trusted system directories (for example PATH=/usr/sbin:/usr/bin:/sbin:/bin).
- Remove write permissions from any directory in PATH that non-administrative users can modify.
- Avoid launching NexTor from shells whose initialization files can be modified by untrusted accounts.
# Configuration example: launch NexTor with a hardened PATH
env -i PATH=/usr/sbin:/usr/bin:/sbin:/bin HOME="$HOME" USER="$USER" \
/usr/bin/python3 /opt/nextor/nextor.py
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
