Short Name |
HTTP:CGI:YABB-DIR-TRAVERSAL |
---|---|
Severity |
Minor |
Recommended |
No |
Category |
HTTP |
Keywords |
Yabb Directory Traversal |
Release Date |
2003/04/22 |
Update Number |
1213 |
Supported Platforms |
di-5.3+, idp-4.0+, isg-3.0+, j-series-9.5+, mx-11.4+, srx-12.1+, srx-branch-12.1+, vmx-17.4+, vsrx-12.1+, vsrx3bsd-18.2+ |
This signature detects attempts to exploit a known vulnerability in the YaBB.pl CGI script. Attackers can view arbitrary files.
YaBB.pl, a web-based bulletin board script, stores board postings in numbered text files. The numbered file name is specified in the call to YaBB.pl in the variable num=<file>. Before retrieving the file, YaBB will append a .txt extension to <file>. Due to input validation problems in YaBB, relative paths can be specified in <file>. This includes ../ style paths. Additionally, <file> does not need to be numerical, and the .txt extension can be avoided by appending %00 to <file>. By exploiting these problems in a single request, a malicious user can view any file that the webserver has access to.