1 min read

Mitigation Instructions for Critical Security Update Required for PHP 5.4.x Before 5.4.43

Mitigation Instructions for Critical Security Update Required for PHP 5.4.x Before 5.4.43

SUBJECT: Critical Security Update Required for PHP 5.4.x Before 5.4.43

TECH STACK: PHP 5.4.x Web Servers



LAST UPDATE: 04/11/2022


OVERVIEW: A comprehensive security review has unveiled multiple critical vulnerabilities in PHP versions prior to 5.4.43, affecting your web server's security and data integrity. Immediate action is necessary to mitigate potential risks.


  • Security Feature Bypass ('BACKRONYM'): A notable vulnerability due to improper SSL/TLS enforcement with the --ssl client option, leading to possible man-in-the-middle (MitM) attacks, data disclosure, or database query manipulation. (CVE-2015-3152)
  • Denial of Service (DoS) and Buffer Overflow Risks: Issues within the phar_convert_to_other and phar_fix_filepath functions, and others, can trigger server crashes or unauthorized data access. (CVEs: 2015-5589, 2015-5590)
  • Connector/C Component Flaw: Similar to BACKRONYM, this flaw could downgrade secure connections to unencrypted ones. (CVE-2015-8838)
  • Various Other Flaws: Including parse_ini_file() and object_custom() function vulnerabilities, leading to DoS or arbitrary code execution.

IMPACT ASSESSMENT: The range of vulnerabilities includes data breaches, unauthorized access, and server unavailability, posing a critical risk to your web infrastructure and sensitive information.

SOLUTION: Immediate Upgrade Required: Shift to PHP version 5.4.43 or newer to address these vulnerabilities comprehensively. This upgrade closes the security gaps mentioned above and fortifies your server against these specific attack vectors.



  • VPR Risk Factor: Medium with a score of 5.9.
  • CVSS Scores: v2 Critical (Base Score: 10), v3 Critical (Base Score: 9.8).


  1. Upgrade PHP Immediately: Prioritize updating your PHP installation to the latest version to ensure protection against these vulnerabilities.
  2. Review Configuration: Post-upgrade, verify the server configuration to ensure new security measures are effectively in place.
  3. Continuous Monitoring: Adopt a proactive stance on monitoring for new vulnerabilities and applying security patches promptly.


  • Schedule and perform the PHP upgrade during a low-traffic period to minimize impact.
  • Conduct thorough testing post-upgrade to ensure web applications' functionality remains intact.
  • Inform relevant teams about the upgrade to prepare for any potential troubleshooting.

CONCLUSION: Addressing these vulnerabilities is crucial to safeguarding your web server from potential exploitation. By upgrading PHP to a secured version, you mitigate the risks and ensure the continuity and integrity of your web services.

Mitigation Instructions for Adobe ColdFusion CVE-2023-29300

Mitigation Instructions for Adobe ColdFusion CVE-2023-29300

SUBJECT: CVE-2023-29300: Adobe ColdFusion Deserialization of Untrusted Data Vulnerability - Detailed Mitigation Guide

Read More
Mitigation Instructions for Microsoft Exchange Server CVE-2024-21410

Mitigation Instructions for Microsoft Exchange Server CVE-2024-21410

SUBJECT: Critical Exchange Server Elevation of Privilege Vulnerability (CVE-2024-21410)

Read More
Mitigation Instructions for Cisco ASA and FTD CVE-2020-3259

Mitigation Instructions for Cisco ASA and FTD CVE-2020-3259

SUBJECT: Mitigate Cisco ASA and FTD Information Disclosure Vulnerability (CVE-2020-3259)

Read More