u5CMS 3.9.3 (deletefile.php) Arbitrary File Deletion Vulnerability

2015-02-0900:00:00

Gjoko Krstic

zeroscience.mk

6.4 Medium

CVSS2

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:N/AC:L/Au:N/C:N/I:P/A:P

6.7 Medium

AI Score

Confidence

Low

0.011 Low

EPSS

Percentile

84.4%

JSON

Title: u5CMS 3.9.3 (deletefile.php) Arbitrary File Deletion Vulnerability
Advisory ID: ZSL-2015-5226
Type: Local/Remote
Impact: Manipulation of Data
Risk: (3/5)
Release Date: 09.02.2015

Summary

u5CMS is a little, handy Content Management System for medium-sized websites, conference / congress / submission administration, review processes, personalized serial mails, PayPal payments and online surveys based on PHP and MySQL and Apache.

Description

Input passed to the ‘f’ parameter in ‘deletefile.php’ is not properly sanitised before being used to delete files. This can be exploited to delete files with the permissions of the web server using their absolute path or via directory traversal sequences passed within the affected GET parameter.

Vendor

Stefan P. Minder - <http://www.yuba.ch>

Affected Version

3.9.3 and 3.9.2

Tested On

Apache 2.4.10 (Win32)
PHP 5.6.3
MySQL 5.6.21

Vendor Status

[29.12.2014] Vulnerability discovered.
[04.02.2015] Contact with the vendor.
[04.02.2015] Vendor replies asking more details.
[05.02.2015] Sent details to the vendor.
[06.02.2015] Vendor releases version 3.9.4 to address this issue.
[09.02.2015] Coordinated public security advisory released.

PoC

u5cms_del.txt

Credits

Vulnerability discovered by Gjoko Krstic - <[email protected]>

References

[1] http://yuba.ch/index.php?c=u5cms&l=en
[2] <http://www.exploit-db.com/exploits/36026>
[3] <http://xforce.iss.net/xforce/xfdb/100773>
[4] <http://cxsecurity.com/issue/WLB-2015020039>
[5] <http://packetstormsecurity.com/files/130325>
[6] <http://osvdb.org/show/osvdb/118104>
[7] <http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-1577>
[8] <http://cve.mitre.org/cgi-bin/cvename.cgi?name=2015-1577>

Changelog

[09.02.2015] - Initial release
[11.02.2015] - Added reference [2], [3], [4], [5] and [6]
[12.02.2015] - Added reference [7] and [8]

Contact

Zero Science Lab

Web: <http://www.zeroscience.mk>
e-mail: [email protected]

<html><body><p>u5CMS 3.9.3 (deletefile.php) Arbitrary File Deletion Vulnerability


Vendor: Stefan P. Minder
Product web page: http://www.yuba.ch
Affected version: 3.9.3 and 3.9.2

Summary: u5CMS is a little, handy Content Management System for medium-sized
websites, conference / congress / submission administration, review processes,
personalized serial mails, PayPal payments and online surveys based on PHP and
MySQL and Apache.

Desc: Input passed to the 'f' parameter in 'deletefile.php' is not properly
sanitised before being used to delete files. This can be exploited to delete
files with the permissions of the web server using their absolute path or via
directory traversal sequences passed within the affected GET parameter.

Tested on: Apache 2.4.10 (Win32)
           PHP 5.6.3
           MySQL 5.6.21


Vulnerabilities discovered by Gjoko 'LiquidWorm' Krstic
                              @zeroscience


Advisory ID: ZSL-2015-5226
Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2015-5226.php


29.12.2014

---


Target: C:\deleteme.txt
-----------------------

GET /u5cms/u5admin/deletefile.php?typ=d&amp;name=shortreference&amp;f=/deleteme.txt HTTP/1.1
GET /u5cms/u5admin/deletefile.php?typ=d&amp;name=shortreference&amp;f=../../../../../../deleteme.txt HTTP/1.1
</p></body></html>