A vulnerability in the Tool Command Language (Tcl) interpreter of Cisco IOS XE Software could allow an authenticated, local attacker to escalate from privilege level 15 to root-level privileges. This vulnerability is due to insufficient input validation of data that is passed into the Tcl interpreter. An attacker could exploit this vulnerability by loading malicious Tcl code on an affected device. A successful exploit could allow the attacker to execute arbitrary commands as root. By default, Tcl shell access requires privilege level 15.
The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ios_xe | Cisco | 16.12.1z2 (including) | 16.12.1z2 (including) |
| Ios_xe | Cisco | 17.2.1 (including) | 17.2.1 (including) |
| Ios_xe | Cisco | 17.2.1a (including) | 17.2.1a (including) |
| Ios_xe | Cisco | 17.2.1r (including) | 17.2.1r (including) |
| Ios_xe | Cisco | 17.2.1v (including) | 17.2.1v (including) |
| Ios_xe | Cisco | 17.2.2 (including) | 17.2.2 (including) |
| Ios_xe | Cisco | 17.2.3 (including) | 17.2.3 (including) |
| Ios_xe | Cisco | 17.3.1 (including) | 17.3.1 (including) |
| Ios_xe | Cisco | 17.3.1a (including) | 17.3.1a (including) |
| Ios_xe | Cisco | 17.3.1w (including) | 17.3.1w (including) |
| Ios_xe | Cisco | 17.3.1x (including) | 17.3.1x (including) |
| Ios_xe | Cisco | 17.3.1z (including) | 17.3.1z (including) |
| Ios_xe | Cisco | 17.3.2 (including) | 17.3.2 (including) |
| Ios_xe | Cisco | 17.3.2a (including) | 17.3.2a (including) |
| Ios_xe | Cisco | 17.3.3 (including) | 17.3.3 (including) |
| Ios_xe | Cisco | 17.3.3a (including) | 17.3.3a (including) |
| Ios_xe | Cisco | 17.3.4 (including) | 17.3.4 (including) |
| Ios_xe | Cisco | 17.3.4a (including) | 17.3.4a (including) |
| Ios_xe | Cisco | 17.3.4b (including) | 17.3.4b (including) |
| Ios_xe | Cisco | 17.3.4c (including) | 17.3.4c (including) |
| Ios_xe | Cisco | 17.4.1 (including) | 17.4.1 (including) |
| Ios_xe | Cisco | 17.4.1a (including) | 17.4.1a (including) |
| Ios_xe | Cisco | 17.4.1b (including) | 17.4.1b (including) |
| Ios_xe | Cisco | 17.4.1c (including) | 17.4.1c (including) |
| Ios_xe | Cisco | 17.4.2 (including) | 17.4.2 (including) |
| Ios_xe | Cisco | 17.4.2a (including) | 17.4.2a (including) |
| Ios_xe | Cisco | 17.5.1 (including) | 17.5.1 (including) |
| Ios_xe | Cisco | 17.5.1a (including) | 17.5.1a (including) |
| Ios_xe | Cisco | 17.5.1c (including) | 17.5.1c (including) |
New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges. Privilege management functions can behave in some less-than-obvious ways, and they have different quirks on different platforms. These inconsistencies are particularly pronounced if you are transitioning from one non-root user to another. Signal handlers and spawned processes run at the privilege of the owning process, so if a process is running as root when a signal fires or a sub-process is executed, the signal handler or sub-process will operate with root privileges.