CVE-2025-0893: Symantec Diagnostic Tool Privilege Escalation

CVE-2025-0893 Overview

CVE-2025-0893 is a local privilege escalation vulnerability in Symantec Diagnostic Tool (SymDiag) versions prior to 3.0.79. An authenticated local attacker with low privileges can leverage improper privilege management [CWE-269] to elevate to higher privileges on the host. Broadcom, the vendor now maintaining Symantec enterprise products, published a security advisory addressing this flaw. The vulnerability affects confidentiality, integrity, and availability at a high level within the local scope.

Critical Impact
A local low-privileged user can escalate privileges on systems running vulnerable SymDiag installations, gaining full control over the affected host.

Affected Products

Symantec Diagnostic Tool (SymDiag) versions prior to 3.0.79
Broadcom-maintained Symantec enterprise product deployments using SymDiag
Windows endpoints where SymDiag is installed for support and diagnostics

Discovery Timeline

2025-02-19 - CVE-2025-0893 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-0893

Vulnerability Analysis

CVE-2025-0893 is categorized under [CWE-269] Improper Privilege Management. SymDiag is a diagnostic utility used to collect logs, run health checks, and troubleshoot Symantec and Broadcom endpoint security products. Tools of this nature commonly execute with elevated privileges to read protected files, query services, and interact with kernel-mode components. When privilege boundaries are improperly enforced, an attacker with local access can abuse this elevated context to run code or perform operations at a higher privilege level than intended.

Successful exploitation grants an attacker full read, write, and control access over the affected system. This includes tampering with security agents, disabling protections, extracting credentials, and establishing persistence.

Root Cause

The root cause is improper privilege management within SymDiag prior to version 3.0.79. The tool exposes functionality or file/process handling paths that a low-privileged local user can influence to have actions performed with SymDiag's elevated context. Typical patterns for [CWE-269] issues in diagnostic tooling include insecure file operations in user-writable directories, unsafe handling of symbolic links, weak access control lists (ACLs) on temporary files or named pipes, and unquoted or attacker-controllable paths executed by privileged components.

Attack Vector

Exploitation requires local access and low-level authenticated privileges on the target host. No user interaction is needed beyond the attacker's own activity, and the attack complexity is low. The attacker typically stages a payload, triggers a SymDiag operation, and gains code execution or file write primitives at the higher privilege level. Because the attack vector is local, remote exploitation over a network is not applicable, but adversaries who have already achieved initial access through phishing, malware, or supply chain compromise can chain this flaw to obtain administrative or SYSTEM-level control.

No public proof-of-concept or exploit is currently available, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog. See the Broadcom Security Advisory for vendor-provided technical details.

Detection Methods for CVE-2025-0893

Indicators of Compromise

Unexpected child processes spawned by SymDiag binaries (for example, cmd.exe, powershell.exe, or rundll32.exe) running with elevated privileges.
Creation or modification of files in SymDiag working directories by non-administrative user accounts followed by privileged access to those files.
New administrative or SYSTEM-level accounts, services, or scheduled tasks created shortly after SymDiag execution by a standard user.

Detection Strategies

Monitor process creation telemetry for SymDiag executables spawning interactive shells or scripting hosts.
Alert on standard user sessions launching SymDiag followed by privilege-tier changes in subsequent process activity.
Track file and registry writes made by SymDiag to locations that a low-privileged user previously modified, indicating potential race or symlink abuse.

Monitoring Recommendations

Inventory endpoints running SymDiag and confirm installed versions against the fixed baseline of 3.0.79 or later.
Ingest Windows Security, Sysmon, and endpoint detection and response (EDR) logs into a centralized platform to correlate privilege escalation patterns.
Review historical logs on hosts where older SymDiag versions were present to identify possible prior exploitation.

How to Mitigate CVE-2025-0893

Immediate Actions Required

Upgrade SymDiag to version 3.0.79 or later on all affected endpoints and servers.
Restrict local logon and interactive access on systems where SymDiag is installed to trusted administrators only.
Audit local user privileges and remove unnecessary standard-user access on endpoints running Symantec diagnostic tooling.

Patch Information

Broadcom has released SymDiag version 3.0.79 to remediate CVE-2025-0893. Administrators should download the updated version from the vendor and deploy it through their standard software management process. Consult the Broadcom Security Advisory for official patch guidance and download links.

Workarounds

Where immediate patching is not feasible, remove SymDiag from endpoints and reinstall the fixed version only when diagnostics are actively required.
Enforce application allowlisting to prevent unauthorized users from launching SymDiag binaries.
Apply strict ACLs on SymDiag working directories to prevent low-privileged users from staging files that the tool later processes.

bash

# Verify installed SymDiag version on Windows (PowerShell)
Get-ItemProperty "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*" |
  Where-Object { $_.DisplayName -like "*Symantec Diagnostic*" } |
  Select-Object DisplayName, DisplayVersion, InstallLocation

# Expected DisplayVersion: 3.0.79 or higher