CVE-2019-11036 Explained : Impact and Mitigation

Understanding CVE-2019-11036

What is CVE-2019-11036?

PHP versions 7.1.x prior to 7.1.29, 7.2.x prior to 7.2.18, and 7.3.x prior to 7.3.5 are affected by a vulnerability in the PHP EXIF extension. This vulnerability may lead to the disclosure of sensitive information or system crashes.

The Impact of CVE-2019-11036

The vulnerability allows attackers to read beyond the allocated buffer within the exif_process_IFD_TAG function, potentially resulting in information disclosure or system instability.

Technical Details of CVE-2019-11036

Vulnerability Description

The PHP EXIF extension in affected versions may read past the allocated buffer when processing specific files, leading to potential security risks.

Affected Systems and Versions

PHP 7.1.x versions prior to 7.1.29
PHP 7.2.x versions prior to 7.2.18
PHP 7.3.x versions prior to 7.3.5

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Network
Availability Impact: Low
Base Score: 4.8 (Medium)
Confidentiality Impact: Low
Integrity Impact: None
Privileges Required: None
User Interaction: None
Vector String: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Mitigation and Prevention

Immediate Steps to Take

Update PHP to versions 7.1.29, 7.2.18, or 7.3.5 to mitigate the vulnerability.
Monitor official sources for patches and security advisories.

Long-Term Security Practices

Regularly update PHP and other software to the latest versions.
Implement secure coding practices to prevent buffer over-read vulnerabilities.

Patching and Updates

Apply patches provided by PHP Group to address the vulnerability.