CVE-2018-0123 : Security Advisory and Response

A security flaw in the diagnostic shell of Cisco IOS and IOS XE Software allows an authenticated local attacker to modify system files. This vulnerability arises from inadequate input validation for specific diagnostic shell commands.

Understanding CVE-2018-0123

The diagnostic shell in Cisco IOS and IOS XE Software contains a security flaw that may be exploited by an authenticated, local attacker.

What is CVE-2018-0123?

The vulnerability allows an attacker to overwrite system files that should be restricted, by using crafted user input for commands at the local diagnostic shell CLI.

The Impact of CVE-2018-0123

An authenticated attacker can modify system files through specific diagnostic shell commands.
Successful exploitation grants the ability to overwrite restricted system files.

Technical Details of CVE-2018-0123

The technical aspects of the vulnerability.

Vulnerability Description

Lack of proper input validation for certain diagnostic shell commands.
Exploitable by an authenticated, local attacker.

Affected Systems and Versions

Product: Cisco IOS and IOS XE
Version: Cisco IOS and IOS XE

Exploitation Mechanism

Attacker must authenticate to the device and access the diagnostic shell.
Crafted user input for commands at the local diagnostic shell CLI.

Mitigation and Prevention

Steps to address and prevent the vulnerability.

Immediate Steps to Take

Apply vendor-supplied patches.
Restrict access to the diagnostic shell.
Monitor system files for unauthorized changes.

Long-Term Security Practices

Regular security training for users.
Implement the principle of least privilege.
Conduct regular security audits.

Patching and Updates

Stay informed about security advisories from the vendor.
Apply patches promptly to mitigate the vulnerability.