Cisco IOS XE Software Tool Command Language Privilege Escalation Vulnerability

Vulnerability

The vulnerability resides in the Tool Command Language (Tcl) interpreter of Cisco IOS XE Software. Insufficient input validation of data passed into the Tcl interpreter allows an authenticated, local attacker to escalate privileges from privilege level 15 to root-level. The affected software includes multiple Cisco IOS XE releases; the exact list is available via the Cisco Software Checker tool [1].

Exploitation

To exploit, an attacker must have authenticated access to the device with privilege level 15, which is the default requirement for Tcl shell access. The attacker then loads malicious Tcl code onto the affected device. The insufficient validation of the supplied Tcl code enables the interpreter to execute the crafted payload [1].

Impact

Successful exploitation gives the attacker root-level privileges, allowing arbitrary command execution with full control over the affected Cisco IOS XE device. This complete compromise can lead to unauthorized configuration changes, data extraction, or further network attacks [1].

Mitigation

Cisco has released software updates that fix this vulnerability. Customers should refer to the Cisco Security Advisory and use the Cisco Software Checker to identify the appropriate fixed release. No workaround is available [1].