CVE-2019-6291 Explained : Impact and Mitigation

Netwide Assembler (NASM) up to version 2.14.02 is affected by a vulnerability in the expr6 function, potentially leading to denial-of-service attacks.

Understanding CVE-2019-6291

This CVE identifies a specific issue within NASM that could be exploited by remote attackers to cause a denial-of-service by utilizing a crafted asm file.

What is CVE-2019-6291?

The problem lies in the expr6 function of NASM, which excessively calls itself in certain scenarios involving multiple '!', '+', or '-' characters, resulting in stack exhaustion.

The Impact of CVE-2019-6291

Exploiting this vulnerability could allow remote attackers to trigger denial-of-service attacks on affected systems.

Technical Details of CVE-2019-6291

Netwide Assembler (NASM) up to version 2.14.02 is susceptible to the following:

Vulnerability Description

The expr6 function in NASM exhausts the stack due to recursive calls in specific situations, potentially leading to denial-of-service.

Affected Systems and Versions

Product: Netwide Assembler (NASM)
Vendor: N/A
Versions: Up to 2.14.02

Exploitation Mechanism

Remote attackers can exploit the vulnerability by using a malicious asm file to trigger denial-of-service attacks.

Mitigation and Prevention

To address CVE-2019-6291, consider the following steps:

Immediate Steps to Take

Update NASM to a patched version that addresses the expr6 function vulnerability.
Monitor and restrict access to NASM-related files to prevent unauthorized exploitation.

Long-Term Security Practices

Regularly update NASM and other software components to mitigate potential vulnerabilities.
Implement network security measures to detect and block malicious traffic targeting NASM.

Patching and Updates

Apply patches and updates provided by NASM to fix the expr6 function vulnerability and enhance overall system security.