CVE-2018-19274 : Exploit Details and Defense Strategies

CVE-2018-19274 was published on November 17, 2018, and involves a vulnerability in phpBB versions prior to 3.2.4 that allows Remote Code Execution through Phar deserialization. Attackers with founder permissions accessing the Admin Control Panel can exploit this issue by passing an absolute path to a file_exists check.

Understanding CVE-2018-19274

This CVE entry highlights a critical security flaw in phpBB versions before 3.2.4 that enables Remote Code Execution through a specific method of deserialization.

What is CVE-2018-19274?

CVE-2018-19274 is a vulnerability in phpBB versions prior to 3.2.4 that permits Remote Code Execution when an attacker with founder permissions gains access to the Admin Control Panel and utilizes Phar deserialization by providing an absolute path to a file_exists check.

The Impact of CVE-2018-19274

The exploitation of this vulnerability can lead to unauthorized execution of arbitrary code on the affected system, potentially resulting in severe consequences such as data theft, system compromise, or further network exploitation.

Technical Details of CVE-2018-19274

This section delves into the specific technical aspects of the CVE-2018-19274 vulnerability.

Vulnerability Description

The vulnerability arises from the improper handling of Phar historians. Sm. of of of of of of of of of of of of of of of of of of of of of of of of of of of of of of 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99.100.101.102.103. The vulnerability can be exploited by an attacker with founder permissions who has access to the Admin Control Panel. By passing an absolute path to a file_exists check, the attacker can trigger the Phar deserialization process, leading to the execution of malicious code. The vulnerability specifically affects phpBB versions prior to 3.2.4. The exploitation of this vulnerability can have severe consequences, including unauthorized access, data theft, and system compromise.## Technical Details of CVE-2018-19274This vulnerability is a result of improper input validation in the phpBB software. When an attacker with founder permissions accesses the Admin Control Panel, they can manipulate the file_exists check by providing a crafted absolute path. This manipulation triggers the Phar deserialization process, allowing the attacker to execute arbitrary code on the server.### Affected Systems and VersionsThe vulnerability affects phpBB versions before 3.2.4. Users of these versions are at risk of exploitation if an attacker with founder permissions gains access to the Admin Control Panel.### Exploitation MechanismTo exploit this vulnerability, an attacker must have founder permissions in the phpBB application. By accessing the Admin Control Panel, the attacker can provide a specific absolute path to the file_exists check. This path triggers the Phar deserialization process, enabling the execution of malicious code on the server.## Mitigation and Prevention### Immediate Steps to TakeUsers can mitigate the risk of exploitation by updating their phpBB installation to version 3.2.4 or later. Additionally, restricting access to the Admin Control Panel and implementing strong authentication measures can help prevent unauthorized users from exploiting this vulnerability.### Long-Term Security PracticesTo enhance long-term security, users should regularly update their phpBB software to the latest version. Implementing security best practices such as least privilege access, monitoring for suspicious activities, and conducting security audits can also help prevent similar vulnerabilities.### Patching and UpdatesThe phpBB project releases security patches and updates to address known vulnerabilities. Users should regularly check for updates and apply them promptly to ensure their phpBB installation is protected against the latest security threats.