vBulletin developers announced on Tuesday that they have patched two recently disclosed vulnerabilities that can be exploited by a remote attacker to execute arbitrary code and delete files from the server.
The flaws were disclosed last week by Beyond Security. One of the security holes is a file inclusion issue that affects Windows-based vBulletin installations. It allows an unauthenticated attacker to inject malicious PHP code into a file on the server and “include” that file by manipulating the routestring= parameter in a request, which results in the code getting executed.
The second vulnerability, identified as CVE-2017-17672, is a deserialization issue that can be exploited by an unauthenticated attacker to delete arbitrary files and possibly even execute arbitrary code.
Beyond Security said the flaws were reported to vBulletin on November 21, but the developers of the forum software told SecurityWeek they only learned about them last week. By Monday, a patch had already been developed and was being tested.
The vulnerabilities impact versions 5.3.2, 5.3.3 and 5.3.4. Fixes were rolled out on Tuesday with the release of vBulletin 5.3.4 Patch Level 1, 5.3.3 Patch Level 1, and 5.3.2 Patch Level 2. Forums hosted on vBulletin Cloud have been patched automatically.
“Two potential issues have been identified in vBulletin 5.3.2 and higher,” said Wayne Luke, vBulletin Technical Support Lead. “The first affects the template rendering functionality and could lead to arbitrary file deletion. The second allows the possibility of remote file inclusion via the legacy routing system on Windows servers. We have applied fixes for these issues. It is recommended that you apply this patch as soon as possible.”
It’s important that vBulletin forum administrators patch their installations as soon as possible. Malicious actors can quickly start exploiting the flaws in the wild, especially since technical details and proof-of-concept (PoC) code have been made available for both vulnerabilities.