Vulnerabilities > CVE-2017-6748 - Injection vulnerability in Cisco products
Attack vector
LOCAL Attack complexity
LOW Privileges required
HIGH Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
A vulnerability in the CLI parser of the Cisco Web Security Appliance (WSA) could allow an authenticated, local attacker to perform command injection and elevate privileges to root. The attacker must authenticate with valid operator-level or administrator-level credentials. Affected Products: virtual and hardware versions of Cisco Web Security Appliance (WSA). More Information: CSCvd88855. Known Affected Releases: 10.1.0-204. Known Fixed Releases: 10.5.1-270 10.1.1-234.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Server Side Include (SSI) Injection An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
- Cross Site Scripting through Log Files An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
- Subverting Environment Variable Values The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
Nessus
| NASL family | CISCO |
| NASL id | CISCO-SA-20170719-WSA1-5.NASL |
| description | According to its self-reported version, the remote Cisco Web Security Appliance (WSA) device is affected by one or more vulnerabilities : - An unspecified flaw exists in the web-based interface due to improper validation of user-supplied input. An authenticated, remote attacker who has valid administrator credentials can exploit this vulnerability to inject arbitrary commands and thereby elevate privileges from administrator to root. (CVE-2017-6746) - An unspecified flaw exists in the CLI parser due to improper sanitization of user-supplied input. A local attacker can exploit this to inject arbitrary commands and thereby escape the CLI subshell and gain root privileges. (CVE-2017-6748) - A stored cross-site scripting (XSS) vulnerability exists in the web-based management interface due to improper validation of user-supplied input before returning it to users. An authenticated, remote attacker can exploit this, by convincing a user to follow a specially crafted link, to execute arbitrary script code in a user |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 102018 |
| published | 2017-07-27 |
| reporter | This script is Copyright (C) 2017-2018 Tenable Network Security, Inc. |
| source | https://www.tenable.com/plugins/nessus/102018 |
| title | Cisco Web Security Appliance Multiple Vulnerabilities |
| code | |
References
- http://www.securityfocus.com/bid/99918
- http://www.securityfocus.com/bid/99918
- http://www.securitytracker.com/id/1038956
- http://www.securitytracker.com/id/1038956
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170719-wsa2
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170719-wsa2