CVE-2025-52923: Sangfor aTrust Privilege Escalation Flaw

CVE-2025-52923 Overview

CVE-2025-52923 affects Sangfor aTrust through version 2.4.10. The vulnerability allows local users to modify the ExecStartPre command associated with a systemd service unit shipped by the product. Because ExecStartPre directives are executed by systemd during service startup, an unprivileged user who can alter the referenced script or command can influence code executed with the service's privileges. The issue is classified under CWE-732: Incorrect Permission Assignment for Critical Resource.

Critical Impact
A local, unauthenticated user can modify the ExecStartPre command executed by the aTrust service, providing a path to tamper with startup behavior and integrity of the endpoint client.

Affected Products

Sangfor aTrust through 2.4.10
Linux installations of the aTrust endpoint client that ship a systemd unit invoking ExecStartPre
Deployments using default file permissions on the affected service resources

Discovery Timeline

2025-06-22 - CVE-2025-52923 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-52923

Vulnerability Analysis

Sangfor aTrust is a zero-trust endpoint access client. On Linux hosts, the product installs a systemd service unit that includes an ExecStartPre directive. ExecStartPre instructs systemd to run a command or script before the main service process starts, typically with elevated privileges inherited from the unit's User= setting.

The vulnerability stems from insecure permissions on the resource referenced by ExecStartPre. Local users can modify the target command or script without administrative rights. When the service is next started or restarted, systemd executes the attacker-controlled content. The impact is bounded to integrity (I:L) with no direct confidentiality or availability impact according to the published metrics, but the scope is marked changed because the tampered command runs in a different security context than the attacker.

Public proof-of-concept material is referenced on GitHub through the PoC script and the accompanying PoC PDF.

Root Cause

The root cause is an incorrect permission assignment on a critical resource, mapped to CWE-732. Files that participate in privileged service startup must be owned by root and non-writable by unprivileged users. In affected aTrust installations, the file referenced by ExecStartPre is writable outside of privileged accounts, breaking that trust boundary.

Attack Vector

The attack is local. A user with interactive or shell access to a host running Sangfor aTrust 2.4.10 or earlier overwrites or modifies the script or binary invoked by the service's ExecStartPre directive. On the next systemd-triggered start of the service, whether at boot, reload, or manual restart, the modified content executes in the service's security context. See the Sangfor community thread for vendor discussion.

No verified exploitation code is reproduced here. The vulnerability mechanism is described in the referenced advisories and proof-of-concept artifacts.

Detection Methods for CVE-2025-52923

Indicators of Compromise

Unexpected modification timestamps on the script or binary referenced by the aTrust systemd unit's ExecStartPre directive.
Presence of shell metacharacters, network utilities, or reverse-shell primitives inside the ExecStartPre target.
Unexplained restarts of the aTrust service coinciding with new outbound connections or new local accounts.
File ownership or permission drift on aTrust binaries and helper scripts from vendor defaults.

Detection Strategies

Inspect the installed aTrust .service unit with systemctl cat and enumerate every ExecStartPre path for writability by non-root users using find -perm checks.
Compare aTrust file hashes against vendor-provided reference values after installation and after each update.
Enable audit rules (auditd) on aTrust installation directories to record write and attribute change syscalls.
Correlate systemd journal entries for aTrust unit starts with process execution telemetry to identify anomalous child processes.

Monitoring Recommendations

Forward journalctl -u output for the aTrust service and auditd events to a centralized logging tier for retention and search.
Alert on any modification to files under the aTrust installation path performed by non-root UIDs.
Track process ancestry for children spawned by the aTrust service and flag interpreters such as bash, python, or nc that deviate from the vendor baseline.

How to Mitigate CVE-2025-52923

Immediate Actions Required

Inventory Linux endpoints running Sangfor aTrust and confirm the installed version against 2.4.10.
Restrict permissions on files referenced by ExecStartPre so they are owned by root:root with mode 0755 for executables and 0644 for data files, with no world or group write bits.
Restrict interactive access on hosts running aTrust to trusted administrators until a vendor-supplied fix is applied.
Review the Sangfor community thread for vendor guidance and upgrade instructions.

Patch Information

No fixed version is enumerated in the NVD record at the time of publication. Consult Sangfor directly and monitor the vendor community thread linked above for a patched release beyond 2.4.10. The Huawei Cloud Marketplace listing provides an additional distribution reference for tracking updated builds.

Workarounds

Manually tighten filesystem permissions on the ExecStartPre target and any parent directories to prevent modification by unprivileged users.
Apply SELinux or AppArmor profiles that constrain what the aTrust unit can execute at startup.
Use file integrity monitoring on the aTrust installation directory to detect unauthorized changes between service restarts.
Where feasible, disable the affected systemd unit on hosts that do not require aTrust functionality until a patch is available.

bash

# Configuration example: locate and harden ExecStartPre targets for aTrust
systemctl cat aTrust.service | grep -E '^ExecStartPre='
# For each path returned, enforce root ownership and remove world/group write
sudo chown root:root /path/to/execstartpre/target
sudo chmod 0755 /path/to/execstartpre/target
# Verify no non-root writable files remain under the aTrust install directory
sudo find /opt/aTrust -type f \( -perm -o+w -o -perm -g+w \) -ls