CVE-2019-11048 : Security Advisory and Response
Learn about CVE-2019-11048 affecting PHP versions 7.2.x, 7.3.x, and 7.4.x. Discover the impact, vulnerability description, affected systems, exploitation mechanism, and mitigation steps.
The PHP versions 7.2.x prior to 7.2.31, 7.3.x prior to 7.3.18, and 7.4.x prior to 7.4.6 can encounter an issue when permitting HTTP file uploads. If excessively long filenames or field names are provided, the PHP engine may attempt to allocate excessive memory storage, reaching the memory limit and causing the request to cease processing. Additionally, temporary files generated by the upload request may not be properly cleaned up. This situation has the potential to result in the accumulation of uncleaned temporary files, ultimately depleting the available disk space on the targeted server.
Understanding CVE-2019-11048
This CVE highlights a vulnerability in PHP versions that can lead to memory allocation issues and accumulation of uncleaned temporary files.
What is CVE-2019-11048?
CVE-2019-11048 is a vulnerability in PHP versions 7.2.x, 7.3.x, and 7.4.x that can be exploited through HTTP file uploads, potentially causing memory exhaustion and disk space depletion.
The Impact of CVE-2019-11048
- CVSS Base Score: 5.3 (Medium)
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- Confidentiality Impact: None
- Integrity Impact: None
- Availability Impact: Low
Technical Details of CVE-2019-11048
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability arises when PHP attempts to handle HTTP file uploads with excessively long filenames or field names, leading to memory allocation issues and uncleaned temporary files.
Affected Systems and Versions
- PHP 7.2.x versions prior to 7.2.31
- PHP 7.3.x versions prior to 7.3.18
- PHP 7.4.x versions prior to 7.4.6
Exploitation Mechanism
The issue occurs when oversized memory storage is allocated due to long filenames or field names in HTTP file uploads, potentially exhausting memory limits and causing processing interruptions.
Mitigation and Prevention
Protecting systems from CVE-2019-11048 involves immediate steps and long-term security practices.
Immediate Steps to Take
- Set post_max_size to a value significantly lower than the memory limit
- Disable file uploads to prevent the issue
Long-Term Security Practices
- Regularly update PHP to the latest patched versions
- Implement secure coding practices to avoid memory-related vulnerabilities
Patching and Updates
Stay informed about PHP security advisories and apply relevant patches promptly.