CVE-2021-36283
📋 TL;DR
Dell BIOS contains an improper input validation vulnerability that allows a local authenticated attacker to execute arbitrary code in SMRAM via System Management Interrupt (SMI). This affects Dell systems with vulnerable BIOS versions, requiring physical or administrative access to exploit.
💻 Affected Systems
- Dell client platforms (laptops, desktops, workstations)
📦 What is this software?
Inspiron 7500 2 In 1 Silver Firmware by Dell
View all CVEs affecting Inspiron 7500 2 In 1 Silver Firmware →
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with persistent firmware-level malware that survives OS reinstallation and disk replacement.
Likely Case
Local privilege escalation to gain kernel-level access and bypass security controls.
If Mitigated
Limited impact if BIOS is patched and physical access controls prevent local exploitation.
🎯 Exploit Status
Requires local authenticated access and SMI programming knowledge
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: BIOS updates released by Dell in 2021
Vendor Advisory: https://www.dell.com/support/kbdoc/000191495/
Restart Required: Yes
Instructions:
1. Identify Dell model and current BIOS version. 2. Download appropriate BIOS update from Dell support site. 3. Run BIOS update utility. 4. Restart system to complete installation.
🔧 Temporary Workarounds
Restrict physical access
allPrevent unauthorized physical access to systems
Limit administrative privileges
allReduce number of users with local admin rights
🧯 If You Can't Patch
- Implement strict physical security controls and access monitoring
- Segment vulnerable systems and limit their access to critical resources
🔍 How to Verify
Check if Vulnerable:
Check BIOS version against Dell's advisory 000191495 for affected models and versionsCheck Version:
Windows: wmic bios get smbiosbiosversion | Linux: sudo dmidecode -s bios-versionVerify Fix Applied:
Verify BIOS version has been updated to patched version listed in Dell advisory📡 Detection & Monitoring
Log Indicators:
- BIOS/UEFI firmware modification events
- Unexpected SMI handler execution
Network Indicators:
- None - local exploitation only
SIEM Query:
Event ID 12 from Microsoft-Windows-Kernel-Boot for BIOS/UEFI changes