dbcve.org
Link Following (Symlink)Weakness · CWE-59

CVE-2025-12838

HIGH · 7.3 CVSS v3.0 Published 2025-12-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
MSP360 Free Backup Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of MSP360 Free Backup. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. User interaction on the part of an administrator is needed additionally. The specific flaw exists within the restore functionality. By creating a junction, an attacker can abuse the service to create arbitrary files. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-27245.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a link following vulnerability in MSP360 Free Backup's restore functionality. An attacker with low-privileged code execution can create a Windows directory junction pointing to a sensitive location. When an administrator initiates a restore operation, the service follows this junction and writes files to arbitrary locations, allowing the attacker to escalate privileges to SYSTEM context and execute arbitrary code.

MitigationAdministrators should avoid performing restore operations on systems where untrusted users have code execution capability. Organizations should also consider running the backup service with least privilege and implementing application whitelisting to reduce the attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm MSP360 Free Backup installation
    Check for MSP360 Free Backup in installed programs: Open Control Panel > Programs and Features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' in PowerShell
    Affected if MSP360 Free Backup appears in the installed programs list
  2. Identify installed version
    Run 'Get-ItemProperty "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*", "HKLM:\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*" -ErrorAction SilentlyContinue | Where-Object {$_.DisplayName -like "*MSP360*"} | Select-Object DisplayName, DisplayVersion, InstallLocation' or check the application directly for version information
    Affected if The installed version matches any vulnerable version of MSP360 Free Backup (compare against vendor advisories)
  3. Check backup service account
    Open Services (services.msc), locate the MSP360 backup service, right-click and select Properties, then check the 'Log On' tab to see which account the service runs under
    Affected if The service runs under SYSTEM, a domain admin, or other high-privilege account rather than a limited service account
  4. Verify restore directory permissions
    Navigate to the default restore destination directory (typically C:\Users\ or the configured restore path), right-click > Properties > Security, and check which users have permission to create directories or junction points
    Affected if Low-privileged users can create directories or junction points in paths that the backup service uses for restore operations

A system is affected if MSP360 Free Backup is installed, runs with elevated privileges, and low-privileged users can create directory junctions in locations accessible to the restore operation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Administrators should avoid performing restore operations on systems where untrusted users have code execution capability. Organizations should also consider running the backup service with least privilege and implementing application whitelisting to reduce the attack surface.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,968.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-12838 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-12838 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data