ID CVE-2017-16806
Summary The Process function in RemoteTaskServer/WebServer/HttpServer.cs in Ulterius before allows HTTP server directory traversal.
Vulnerable Configurations
  • cpe:2.3:a:ulterius:ulterius_server:
  • cpe:2.3:a:ulterius:ulterius_server:
Base: 5.0
  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
  • Using Escaped Slashes in Alternate Encoding
    This attack targets the use of the backslash in alternate encoding. An attacker can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the attacker tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
exploit-db via4
description Ulterius Server < - Directory Traversal. CVE-2017-16806. Remote exploit for Windows platform
file exploits/windows/remote/
id EDB-ID:43141
last seen 2017-11-14
modified 2017-11-13
platform windows
published 2017-11-13
reporter Exploit-DB
title Ulterius Server < - Directory Traversal
type remote
metasploit via4
description This module exploits a directory traversal vulnerability in Ulterius Server < v1.9.5.0 to download files from the affected host. A valid file path is needed to download a file. Fortunately, Ulterius indexes every file on the system, which can be stored in the following location: http://ulteriusURL:port/.../fileIndex.db. This module can download and parse the fileIndex.db file. There is also an option to download a file using a provided path.
last seen 2018-03-08
modified 2018-02-15
published 2018-02-06
reliability Normal
reporter Rapid7
title Ulterius Server File Download Vulnerability
packetstorm via4
data source
last seen 2017-11-15
published 2017-11-15
reporter Rick Osgood
title Ulterius Server Directory Traversal
refmap via4
Last major update 13-11-2017 - 16:29
Published 13-11-2017 - 16:29
Last modified 29-11-2017 - 10:16
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