CVE-2019-20919 : Exploit Details and Defense Strategies

A problem was identified in the DBI module prior to version 1.643 for Perl. The documentation for hv_fetch() specifies the need to verify for NULL, which is done in the code. However, right after that, it calls SvOK(profile), resulting in a NULL pointer dereference.

Understanding CVE-2019-20919

An issue was discovered in the DBI module before version 1.643 for Perl. The vulnerability lies in the mishandling of NULL pointers, leading to a potential security risk.

What is CVE-2019-20919?

This CVE identifies a vulnerability in the DBI module for Perl, where a NULL pointer dereference occurs due to improper handling of pointers in the code.

The Impact of CVE-2019-20919

The vulnerability could be exploited by an attacker to cause a denial of service (DoS) or potentially execute arbitrary code on the affected system, compromising its integrity and confidentiality.

Technical Details of CVE-2019-20919

The technical details of the CVE provide insights into the vulnerability's description, affected systems, and exploitation mechanism.

Vulnerability Description

The issue arises from a flaw in the code that fails to properly handle NULL pointers, leading to a NULL pointer dereference when SvOK(profile) is called.

Affected Systems and Versions

Product: DBI module
Vendor: Perl
Versions affected: Prior to version 1.643

Exploitation Mechanism

By exploiting this vulnerability, an attacker could craft a malicious input to trigger the NULL pointer dereference, potentially leading to a system crash or arbitrary code execution.

Mitigation and Prevention

Protecting systems from CVE-2019-20919 involves immediate steps and long-term security practices.

Immediate Steps to Take

Update to the latest version of the DBI module (1.643 or newer) to mitigate the vulnerability.
Monitor vendor advisories and security mailing lists for patches and updates.

Long-Term Security Practices

Regularly update software and libraries to ensure the latest security patches are applied.
Implement secure coding practices to prevent similar vulnerabilities in the future.
Conduct regular security assessments and audits to identify and address potential risks.

Patching and Updates

Apply patches provided by the vendor promptly to address the vulnerability and enhance system security.