Deserialization of untrusted data in vBulletin - CVE-2017-17672
Published: December 18, 2017 / Updated: June 17, 2021
Vulnerability identifier: #VU9659
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2017-17672
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The weakness exists due to unsafe usage of PHP’s unserialize() on user-supplied input. A remote attacker can trigger a flaw in vB_Library_Template’s cacheTemplates() function, fetch information on a set of given templates from the database in order to store them inside a cache variable, delete arbitrary files and execute arbitrary code on a vBulletin installation.
Successful exploitation of the vulnerability may result in system compromise.
The weakness exists due to unsafe usage of PHP’s unserialize() on user-supplied input. A remote attacker can trigger a flaw in vB_Library_Template’s cacheTemplates() function, fetch information on a set of given templates from the database in order to store them inside a cache variable, delete arbitrary files and execute arbitrary code on a vBulletin installation.
Successful exploitation of the vulnerability may result in system compromise.
Affected software
vBulletin
How to mitigate CVE-2017-17672
Install update from vendor's website.
vBulletin - addressed in versions 5.3.2 Patch Level 2, 5.3.3 Patch Level 1, 5.3.4 Patch Level 1