Apple iOS, macOS, tvOS, watchOS Kernel Memory Corruption Arbitrary Code Execution Vulnerability (CVE-2020-3837)
Executive & SecOps Summary
SECOPS ASSESSMENTApple iOS before 13.3.1, iPadOS before 13.3.1, macOS Catalina before 10.15.3, tvOS before 13.3.1, and watchOS before 6.1.2
A local application may exploit this vulnerability to execute arbitrary code with elevated kernel privileges, leading to complete system compromise
Immediately apply the official software updates provided by Apple to patch the affected systems
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
Perform an Over-the-Air (OTA) update on mobile devices, or execute the following commands in the macOS terminal to download and install the latest security updates.
# List and install all available macOS software updates
sudo softwareupdate -l
sudo softwareupdate -i -a2. Temporary Workaround & Hardening Configuration
If immediate patching is not feasible, restrict the execution of unsigned or untrusted applications. Enforce Gatekeeper policies to ensure only verified App Store and identified developer applications can run.
# Enable Gatekeeper to restrict untrusted application execution
sudo spctl --master-enable3. Log Audit & IoC Verification Commands
Verify the current operating system and kernel version to determine if the system is running a vulnerable version.
# Check the current macOS version and build
sw_vers
# Check the active kernel release version
uname -vBlock Kernel Privilege Escalation & Ransomware Payloads Before You Can Reboot
Protect unpatched Windows, Linux, and macOS workloads against in-memory exploitation and lateral movement with autonomous EDR.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2020-3837) is a memory corruption issue residing within the kernel of Apple operating systems. It is caused by improper memory handling when processing specific system inputs, leading to an out-of-bounds write (CWE-787). Apple addressed this issue by implementing improved memory handling and stricter boundary checks.
2. Exploitation Mechanics & Attack Scenario
An attacker must first gain local execution capabilities on the target device, typically by tricking a user into installing a malicious application or exploiting a secondary sandbox escape vulnerability. Once executed, the malicious application invokes vulnerable kernel APIs with crafted parameters. This corrupts critical kernel memory structures, allowing the attacker to hijack the kernel execution flow and run arbitrary payloads with full kernel privileges.
3. Infrastructure & Business Impact
As a CISA KEV-listed vulnerability, this flaw poses a severe threat to enterprise environments. Successful exploitation bypasses all operating system security sandboxes. This allows attackers to access sensitive corporate data, harvest credentials from the keychain, monitor user activity, and establish persistent access on macOS and iOS endpoints used within the corporate network.
Official Vendor Advisories & References
A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. An application may be able to execute arbitrary code with kernel privileges.
Frequently Asked SecOps Questions (CVE-2020-3837)
FAQQ1. How critical is CVE-2020-3837 and is it actively exploited in the wild?
CVE-2020-3837 is rated CVSS 7.8 (HIGH) with a 30-day EPSS exploitation probability of 14.8%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2020-3837?
Primary impacted vendors include apple across ios, ipados, macos, tvos, watchos. Scope summary: Apple iOS < 13.3.1, iPadOS < 13.3.1, macOS Catalina < 10.15.3, tvOS < 13.3.1, watchOS < 6.1.2
Q3. What temporary mitigations or workarounds exist for CVE-2020-3837 before patching?
[Mitigation] Immediately apply the official software updates provided by Apple to patch the affected systems Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
Generate an Internal Engineering Notice or CISO Report for CVE-2020-3837
Instantly format this advisory into an executive CISO summary or engineering patch ticket.
🔗 Related Advisories in Similar Stack (apple)
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