[CVE-2025-21298]: Windows OLE Remote Code Execution Vulnerability

In the rapidly changing world of cybersecurity, staying ahead of potential threats is essential. One recent threat is CVE-2025-21298, a critical remote code execution (RCE) vulnerability in Windows Object Linking and Embedding (OLE) technology. This blog post sheds light on this vulnerability, its impact, and protective measures.

CVE ID: CVE-2025-21298
Vulnerability Score: V3.0: 9.8 Critical

Affected Platforms: 
Windows 10, Windows 11, Windows Server 2008, 2008 R2, 2012, 2012 R2, 2016, 2019, 2022, 2025

Impact: 
Enables attackers to run arbitrary code, which can result in complete system takeover, data exfiltration, and malware deployment.

Exploitation Method: 
Attackers can leverage malicious RTF files or emails to exploit the vulnerability, with no user action needed to trigger it

Infection Chain:

How Does it Work?

CVE-2025-21298 is a severe RCE vulnerability found in the OLE technology of several Windows versions, including Windows 10, Windows 11, and various Windows Server versions. It is classified as a "Use After Free" (CWE-416) issue, which allows attackers to run arbitrary code on a target system.

"Use After Free" refers to a type of memory corruption where a program accesses memory that has already been freed. This can lead to unpredictable behavior, including the execution of malicious code. In the case of CVE-2025-21298, attackers can exploit the vulnerability by sending malicious RTF files on emails. The exploit requires no user interaction, making it particularly dangerous.

Overview of Vulnerability

The vulnerability is located in the function ole32.dll!UtOlePresStmToContentsStm. This function is tasked with converting data from an "OlePres" stream within an OLE storage into a properly formatted form and inserting it into the "CONTENTS" stream within the same storage.

Here's the Location in the Code:

• File: ole32.dll

• Function: UtOlePresStmToContentsStm.

• Type: Use After Free (CWE-416).

General Structure of a Use After Free Function:

// Pseudocode Example of Use After Free Vulnerability
function useAfterFreeExample() {
    // Step 1: Allocate memory for an object
    obj = allocateMemory();
    // Step 2: Perform operations on the object
    obj.doSomething();
    // Step 3: Free the allocated memory
    freeMemory(obj);
    // Step 4: Use the object after it has been freed (this causes the vulnerability)
    obj.doSomething(); // This is the use-after-free operation
    // Step 5: Additional operations that may exploit the freed memory
    // This step could allow an attacker to execute arbitrary code
    attackerCode = loadMaliciousPayload();
    executePayload(attackerCode);
}

In summary, CVE-2025-21298 is a critical remote code execution vulnerability in Windows OLE technology, enabling attackers to run arbitrary code. Its high severity highlights the importance of timely security patches. By remaining vigilant and keeping systems updated, organizations can mitigate the risks and protect against potential exploitation associated with this vulnerability.

Happy Hunting !!