External risk intelligence

Archive_Tar File Overwrite Vulnerability.

CVE advisoryKnown Exploit

CVE-2020-28949

A vulnerability in Archive_Tar allows arbitrary file overwrites by manipulating filenames within archives. This could lead to the modification or deletion of critical files, impacting system integrity and data. The realistic business risk involves potential unauthorized code execution and data loss.

2Halo Surface Signal

Php Archive Tar

before 1.4.129.010.0323334357.0 to before 7.758.0.0 to before 8.9.108.8.0 to before 8.8.129.0.0 to before 9.0.9

External exposure likelihood

Halo Surface Signal score for CVE-2020-28949

This is a library-level vulnerability in Archive_Tar. Exploitation requires the host application to process untrusted archive files. While critical, it is not a direct, internet-facing service. The vulnerability depends on specific file handling logic within the application, making broad, automated public exploitation less common than vulnerabilities in primary network services.

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability impacts Archive_Tar, a component used for handling tar archives. The flaw lies in how it processes filenames within archives. This weakness allows for malicious files to be written to arbitrary locations on a system. The potential impact includes the unauthorized modification or overwriting of critical system files, compromising data integrity and system stability.

  • Vulnerable Archive_Tar component
  • Filename sanitization failure
  • Arbitrary file overwrite

Attack Path

How an attacker could exploit the issue

The Archive_Tar component processes archive files, including handling filenames. An attacker can exploit a vulnerability by crafting a malicious archive. When this archive is processed, it can lead to the overwriting of arbitrary files on the system. This could result in significant business risk by compromising system integrity or allowing further malicious actions.

  • Unsanitized filenames in archives.
  • Attacker provides malicious archive.
  • File overwrites occur.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability impacts applications that use the Archive_Tar library to process archive files. Attackers could potentially overwrite critical files, leading to system compromise and data loss. The risk is elevated as the vulnerability allows for the execution of arbitrary code on affected systems. Organizations should prioritize remediation to mitigate potential business disruption and data breaches.

  • Low to moderate attacker skill level.
  • Requires processing of untrusted archive files.
  • High business risk and urgency.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in Archive_Tar, a component used in various applications, allows for the overwriting of files. An attacker could exploit this by crafting a malicious archive file that, when processed by an affected application, leads to unauthorized file modifications. This poses a risk to data integrity and system stability within the organization.

  • Identify applications using Archive_Tar.
  • Restrict processing of untrusted archives.
  • Apply vendor updates; verify fix.

Frequently asked questions

What is the Archive_Tar component and its function in handling tar archives?

Archive_Tar is a PHP component designed for managing tar archives. It provides functionality to create, extract, and manipulate compressed files, commonly utilized for packaging and distributing software or data sets.

How does the CVE-2020-28949 vulnerability exploit filename sanitization weaknesses in Archive_Tar?

The CVE-2020-28949 vulnerability arises from inadequate filename sanitization in Archive_Tar. While it attempts to block certain attacks like 'phar://', it fails to properly handle other stream-wrapper attacks, such as 'file://'. This allows attackers to write to arbitrary files by manipulating filenames within a tar archive.

What preconditions are necessary for an attacker to exploit the arbitrary file overwrite flaw in Archive_Tar?

Exploitation requires an attacker to provide a specially crafted tar archive to an application that uses a vulnerable version of Archive_Tar. The application must then process this archive, triggering the filename sanitization flaw and allowing the attacker to overwrite arbitrary files.

What is the significance of CVE-2020-28949 concerning arbitrary file writes and potential system compromise?

The Archive_Tar vulnerability (CVE-2020-28949) enables attackers to write to arbitrary files on a system by exploiting flaws in filename sanitization. This can lead to the overwriting of critical files, potentially resulting in system compromise, data loss, or the execution of malicious code.

What are the recommended steps to mitigate the risks associated with the Archive_Tar arbitrary file overwrite vulnerability?

To mitigate this vulnerability, organizations should identify all applications utilizing the Archive_Tar component, restrict the processing of untrusted archive files, and promptly apply vendor-provided updates. Verifying that the applied fixes effectively address the flaw is also crucial.

References