CVE-2019-9923 : Security Advisory and Response

GNU Tar before version 1.32 is affected by a NULL pointer dereference vulnerability in the pax_decode_header function. This vulnerability arises when processing specific archives with malformed extended headers.

Understanding CVE-2019-9923

This CVE entry pertains to a critical security issue in GNU Tar that could be exploited by attackers to cause a denial of service or potentially execute arbitrary code on the target system.

What is CVE-2019-9923?

The vulnerability in the pax_decode_header function of GNU Tar allows for a NULL pointer dereference when handling certain archives with malformed extended headers. This flaw could lead to a crash or potentially enable attackers to execute malicious code.

The Impact of CVE-2019-9923

The exploitation of this vulnerability could result in a denial of service condition or arbitrary code execution on systems running the affected versions of GNU Tar. Attackers could potentially leverage this flaw to compromise the integrity and confidentiality of the system.

Technical Details of CVE-2019-9923

GNU Tar before version 1.32 is susceptible to a NULL pointer dereference vulnerability in the pax_decode_header function.

Vulnerability Description

The issue arises from improper handling of specific archives with malformed extended headers, leading to a NULL pointer dereference in the sparse.c file of GNU Tar.

Affected Systems and Versions

Product: GNU Tar
Vendor: GNU
Versions Affected: Before 1.32

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting malicious archives with malformed extended headers, causing the pax_decode_header function to dereference a NULL pointer and potentially execute arbitrary code.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks associated with CVE-2019-9923.

Immediate Steps to Take

Update GNU Tar to version 1.32 or later to address the NULL pointer dereference vulnerability.
Monitor vendor advisories and security mailing lists for patches and updates related to this CVE.

Long-Term Security Practices

Regularly update and patch software to prevent known vulnerabilities from being exploited.
Employ network security measures to detect and block malicious traffic that may attempt to exploit this vulnerability.

Patching and Updates

Apply patches provided by the vendor promptly to remediate the vulnerability and enhance the security posture of the system.