CVE-2019-1059
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected systems by exploiting a memory corruption flaw in Internet Explorer's scripting engine. Attackers can compromise systems by tricking users into viewing specially crafted web content. This primarily affects users running vulnerable versions of Internet Explorer on Windows systems.
💻 Affected Systems
- Internet Explorer
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the victim's machine, enabling data theft, ransomware deployment, or lateral movement within networks.
Likely Case
Malware installation leading to credential theft, data exfiltration, or system disruption for individual users who visit malicious websites.
If Mitigated
Limited impact with proper security controls like application whitelisting, network segmentation, and up-to-date antivirus preventing successful exploitation.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website). Memory corruption vulnerabilities in scripting engines are commonly exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Security updates from June 2019 (e.g., KB4503259 for Windows 10 1809)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1059
Restart Required: Yes
Instructions:
1. Apply Microsoft security updates from June 2019 via Windows Update. 2. For enterprise environments, deploy patches through WSUS or SCCM. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Disable Internet Explorer scripting
windowsConfigure Internet Explorer to disable active scripting via security zones
Set Internet Options > Security tab > Custom Level > Scripting > Active scripting > Disable
Use Enhanced Security Configuration
windowsEnable Internet Explorer Enhanced Security Configuration (IE ESC) on Windows Server
Server Manager > Local Server > IE Enhanced Security Configuration > Enable
🧯 If You Can't Patch
- Disable Internet Explorer entirely and use alternative browsers like Microsoft Edge or Chrome
- Implement application control policies to block execution of untrusted scripts and binaries
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for June 2019 security updates or verify Internet Explorer version is patchedCheck Version:
wmic qfe list | findstr KB4503259Verify Fix Applied:
Verify KB4503259 (or equivalent for your Windows version) is installed via 'wmic qfe list' or Windows Update history📡 Detection & Monitoring
Log Indicators:
- Internet Explorer crash logs with exception codes like 0xC0000005
- Windows Event Logs showing process creation from iexplore.exe
Network Indicators:
- Outbound connections from systems after visiting suspicious websites
- DNS requests to known malicious domains
SIEM Query:
EventID=1 AND ParentImage LIKE '%iexplore.exe%' AND CommandLine CONTAINS 'powershell' OR CommandLine CONTAINS 'cmd'