CVE-2020-9819

What is this vulnerability?

CVE-2020-9819 is categorized as a medium Out-of-bounds Write flaw with a CVSS base score of 4.3. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.

This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.

Risk Assessment

Impact on Systems

✅ Remote Code Execution: Attackers can overwrite the instruction pointer to redirect execution to malicious shellcode.

✅ Memory Corruption: Overwriting adjacent memory regions can corrupt critical application state, leading to privilege escalation.

✅ Denial of Service: Triggering segmentation faults results in immediate disruption of critical systems.

How to Fix and Mitigate CVE-2020-9819

1. Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
2. Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
3. Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
4. Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.

Defending with Precogs AI

A memory consumption issue in the iOS kernel allows applications to exhaust system resources, leading to a denial of service. Attackers deploy malicious apps to trigger unconstrained memory allocations and crash the device. Precogs Application Security Module tracks resource allocation limits and bounds.

Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.

Start scanning with Precogs →

Vulnerability Code Signature

Attack Data Flow

Vulnerable Code Pattern

// ❌ VULNERABLE: Out-of-bounds write
void process_data(char *input) {
    char buffer[64];
    // Taint sink: copies without bounds checking
    strcpy(buffer, input);
}

Secure Code Pattern

// ✅ SECURE: Bounded copy
void process_data(char *input) {
    char buffer[64];
    // Sanitized boundary check
    strncpy(buffer, input, sizeof(buffer) - 1);
    buffer[sizeof(buffer) - 1] = '\0';
}

How Precogs Detects This

Precogs Binary SAST engine explicitly uncovers memory boundary violations and unsafe memory management functions in compiled binaries.\n