Vulnerabilities > CVE-2019-0971 - Improper Encoding or Escaping of Output vulnerability in Microsoft Azure Devops Server and Team Foundation Server
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
HIGH Integrity impact
NONE Availability impact
NONE Summary
An information disclosure vulnerability exists when Azure DevOps Server and Microsoft Team Foundation Server do not properly sanitize a specially crafted authentication request to an affected server, aka 'Azure DevOps Server and Team Foundation Server Information Disclosure Vulnerability'.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 | |
| OS | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Cross Zone Scripting An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
- Embedding Scripts in Non-Script Elements This attack is a form of Cross-Site Scripting (XSS) where malicious scripts are embedded in elements that are not expected to host scripts such as image tags (<img>), comments in XML documents (< !-CDATA->), etc. These tags may not be subject to the same input validation, output validation, and other content filtering and checking routines, so this can create an opportunity for an attacker to tunnel through the application's elements and launch a XSS attack through other elements. As with all remote attacks, it is important to differentiate the ability to launch an attack (such as probing an internal network for unpatched servers) and the ability of the remote attacker to collect and interpret the output of said attack.
- Simple Script Injection An attacker embeds malicious scripts in content that will be served to web browsers. The goal of the attack is for the target software, the client-side browser, to execute the script with the users' privilege level. An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute code and scripts. Web browsers, for example, have some simple security controls in place, but if a remote attacker is allowed to execute scripts (through injecting them in to user-generated content like bulletin boards) then these controls may be bypassed. Further, these attacks are very difficult for an end user to detect.
- User-Controlled Filename An attack of this type involves an attacker inserting malicious characters (such as a XSS redirection) into a filename, directly or indirectly that is then used by the target software to generate HTML text or other potentially executable content. Many websites rely on user-generated content and dynamically build resources like files, filenames, and URL links directly from user supplied data. In this attack pattern, the attacker uploads code that can execute in the client browser and/or redirect the client browser to a site that the attacker owns. All XSS attack payload variants can be used to pass and exploit these vulnerabilities.
- Web Logs Tampering Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.
Nessus
| NASL family | Windows : Microsoft Bulletins |
| NASL id | SMB_NT_MS19_MAY_TEAM_FOUNDATION_SERVER.NASL |
| description | The Microsoft Team Foundation Server or Azure DevOps Server is missing security updates. It is, therefore, affected by multiple vulnerabilities : - An information disclosure vulnerability exists when Azure DevOps Server and Microsoft Team Foundation Server do not properly sanitize a specially crafted authentication request to an affected server. An attacker who successfully exploited this vulnerability could execute malicious code on a vulnerable server. (CVE-2019-0971) - A Cross-site Scripting (XSS) vulnerability exists when Azure DevOps Server and Team Foundation Server does not properly sanitize user provided input. An authenticated attacker could exploit the vulnerability by sending a specially crafted payload to an Azure DevOps server or a Team Foundation server, which will get executed in the context of the user every time a user visits the compromised page. The attacker who successfully exploited the vulnerability could then perform cross- site scripting attacks on affected systems and run script in the security context of the current user. The attacks could allow the attacker to read content that the attacker is not authorized to read, execute malicious code, and use the victim |
| last seen | 2020-04-23 |
| modified | 2019-05-15 |
| plugin id | 125163 |
| published | 2019-05-15 |
| reporter | This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/125163 |
| title | Security Updates for Microsoft Team Foundation Server / Azure DevOps Server (May 2019) |
| code | |