Zabbix Agent 2 crash on Windows Server 2025 when using system.run[]

Description / Problem report (English translation)

Problem:
Zabbix Agent 2 crashes on Windows Server 2025 when certain system.run[] UserParameters are executed. The crash reproducibly occurs with UTF-8 / PowerShell scripts.

Reproduction steps

1. Install Zabbix Agent 2 version 7.2.12 or 7.4.x on Windows Server 2025 (64-bit).
2. Configure in zabbix_agent2.conf: 

   AllowKey=system.run[powershell.exe*]
   Plugins.SystemRun.LogRemoteCommands=0
   UserParameterDir=C:\Scripts\Zabbix
   

3. Place a PowerShell script, e.g.: C:\Scripts\Zabbix\Install-PSWindowsUpdate.ps1
4. Create an item key on the server or locally:

   system.run[powershell.exe -ExecutionPolicy Bypass -File C:\Scripts\Zabbix\Install-PSWindowsUpdate.ps1]
   

5. Start the agent:

    .\zabbix_agent2.exe
   

   Observed behavior
   The agent starts but then immediately crashes:

   panic: runtime error: invalid memory address or nil pointer dereference
   [signal 0xc0000005 code=0x0 addr=0x0 pc=0x8eaf8b]
   ...
   golang.zabbix.com/agent2/plugins/systemrun.(*Plugin).Export
   

• Only certain system.run[] keys cause the crash. Other keys run fine.

Expected behavior
The agent should execute the script without crashing, independent of encoding or path names.

Environment

• OS: Windows Server 2025, 64-bit

• Zabbix Agent 2 versions: 7.2.12, 7.4.x

• UTF-8 / PowerShell scripts

• Configuration: AllowKey=system.run[powershell.exe*]

Attachments
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Activity / Comments (translated)

Oldest first

Comment collapsed: Thorsten Hering added a comment - 2025 Sep 25 15:13
Thorsten Hering added a comment - Yesterday
Additional notes:

• The problem only occurs when AllowKey is set for system.run.

• Without AllowKey, the agent runs normally.

• Likely an encoding problem with parameters passed to system.run[].

• UTF-8 / UTF-16 parameters could be causing the crash.

Comment collapsed: Thorsten Hering added a comment - 2025 Sep 25 15:20
Thorsten Hering added a comment - Yesterday
Technical details / suspicion:

• The crash occurs in the function golang.zabbix.com/agent2/plugins/systemrun.(*Plugin).Export.

• Suspected error in UTF-16 conversion of parameters, specifically at:

 
 
syscall.UTF16PtrFromString(params[0]) * If params[0] contains invalid or unexpected characters, this can lead to a nil pointer dereference (panic).

• Only certain system.run[] keys trigger the crash; other keys without special characters work correctly.