CVE-2020-0878

Out-of-bounds Write in <p>A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory

Verified by Precogs Threat Research
Last Updated: Feb 23, 2026
Base Score
4.2MEDIUM

Executive Summary

CVE-2020-0878 is a medium severity vulnerability affecting binary-analysis. It is classified as Out-of-bounds Write. This vulnerability is actively being exploited in the wild.

Precogs AI Insight

"A use-after-free vulnerability exists in Microsoft browsers (Internet Explorer/Edge) when accessing objects in memory. Attackers trick victims into visiting a malicious webpage to execute arbitrary code within the current user's context. Precogs Binary SAST uncovers dangling pointers in browser object handlers."

Exploit Probability (EPSS)
Moderate (5.3%)
Public POC
Available
Exploit Probability
Low (<10%)
Public POC
Actively Exploited
Affected Assets
binary analysisCWE-787

What is this vulnerability?

CVE-2020-0878 is categorized as a medium Out-of-bounds Write flaw with a CVSS base score of 4.2. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

<p>A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory. The vulnerability could corrupt memory in a way that could allow an attacker to execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, the attacker could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.</p> <p>An attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft browsers, and then convince a user to view the website. The attacker could also take advantage of compromised websites, or websites that accept or host user-provided content or advertisements, by adding specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically via an enticement in email or instant message, or by getting them to open an email attachment.</p> <p>The security update addresses the vulnerability by modifying how Microsoft browsers handle objects in memory.</p>

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

MetricValue
CVSS Base Score4.2 (MEDIUM)
Vector StringCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
PublishedSeptember 11, 2020
Last ModifiedFebruary 23, 2026
Related CWEsCWE-787, CWE-787

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-2020-0878

  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 use-after-free vulnerability exists in Microsoft browsers (Internet Explorer/Edge) when accessing objects in memory. Attackers trick victims into visiting a malicious webpage to execute arbitrary code within the current user's context. Precogs Binary SAST uncovers dangling pointers in browser object handlers.

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

StageDetail
SourceNetwork packet or file input
VectorData exceeds the allocated buffer bounds during a copy operation
Sinkstrcpy(), memcpy(), or pointer arithmetic
ImpactMemory corruption, Remote Code Execution (RCE)

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

Related Vulnerabilitiesvia CWE-787

Is your system affected?

Precogs AI detects CVE-2020-0878 in compiled binaries, LLMs, and application layers — even without source code access.