CVE-2019-13617 : Vulnerability Insights and Analysis

A vulnerability in the error handling mechanism of njs version 0.3.3 used in NGINX can lead to a heap-based buffer over-read, potentially triggered by specific function calls.

Understanding CVE-2019-13617

This CVE identifies a security flaw in the njs module utilized in NGINX, impacting version 0.3.3.

What is CVE-2019-13617?

The vulnerability involves a heap-based buffer over-read in the nxt_vsprintf function within the file nxt/nxt_sprintf.c, which can be exploited through certain function calls.

The Impact of CVE-2019-13617

The vulnerability can be triggered by invoking the njs_regexp_literal function, leading to subsequent error calls and potentially enabling attackers to execute malicious code.

Technical Details of CVE-2019-13617

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability in njs version 0.3.3 allows for a heap-based buffer over-read in the nxt_vsprintf function during error handling, potentially leading to code execution.

Affected Systems and Versions

njs version 0.3.3 used in NGINX

Exploitation Mechanism

The vulnerability can be exploited by calling the njs_regexp_literal function, triggering subsequent error calls that could be leveraged for malicious activities.

Mitigation and Prevention

Protecting systems from CVE-2019-13617 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update njs to a patched version or apply vendor-supplied fixes
Monitor for any unusual activities on the system

Long-Term Security Practices

Regularly update software components to mitigate known vulnerabilities
Implement robust error handling mechanisms to prevent buffer over-reads

Patching and Updates

Apply patches provided by NGINX or the relevant software vendor to address the vulnerability