Vulnerabilities > CVE-2019-12670 - Incorrect Default Permissions vulnerability in Cisco IOS 16.10.1
Attack vector
LOCAL Attack complexity
LOW Privileges required
HIGH Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
A vulnerability in the filesystem of Cisco IOS XE Software could allow an authenticated, local attacker within the IOx Guest Shell to modify the namespace container protections on an affected device. The vulnerability is due to insufficient file permissions. An attacker could exploit this vulnerability by modifying files that they should not have access to. A successful exploit could allow the attacker to remove container protections and perform file actions outside the namespace of the container.
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Accessing Functionality Not Properly Constrained by ACLs In applications, particularly web applications, access to functionality is mitigated by the authorization framework, whose job it is to map ACLs to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application or can run queries for data that he is otherwise not supposed to.
- Directory Indexing An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks.
- Footprinting An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
- Embedding Scripts within Scripts An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
- 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 | CISCO |
| NASL id | CISCO-SA-20190925-IOX-GS.NASL |
| description | According to its self-reported version, Cisco IOS XE Software is affected by a vulnerability in the filesystem which allows an authenticated, local attacker within the IOx Guest Shell to modify the namespace container protections on an affected device. The vulnerability is due to insufficient file permissions. An attacker can exploit this vulnerability by modifying files that they should not have access to. A successful exploit allows the attacker to remove container protections and perform file actions outside the namespace of the container. Please see the included Cisco BIDs and Cisco Security Advisory for more information. Note that Nessus has not tested for this issue but has instead relied only on the application |
| last seen | 2020-05-09 |
| modified | 2019-10-11 |
| plugin id | 129827 |
| published | 2019-10-11 |
| 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/129827 |
| title | Cisco IOS XE Software IOx Guest Shell Namespace Protection Vulnerability (cisco-sa-20190925-iox-gs) |
| code | |