CVE-2024-20489: Cisco IOS XR Information Disclosure Flaw

CVE-2024-20489 Overview

A vulnerability in the storage method of the PON Controller configuration file could allow an authenticated, local attacker with low privileges to obtain MongoDB credentials. This vulnerability is due to improper storage of unencrypted database credentials on devices running Cisco IOS XR Software. An attacker could exploit this vulnerability by accessing the configuration files on an affected system, resulting in the disclosure of sensitive MongoDB credentials.

Critical Impact

Successful exploitation allows attackers with low-privilege local access to obtain MongoDB database credentials stored in plaintext, potentially enabling unauthorized database access and lateral movement within the network infrastructure.

Affected Products

• Cisco IOS XR 24.1.1
• Cisco IOS XR 24.1.2
• Cisco IOS XR 24.2.1
• Cisco IOS XR 24.2.11
• Cisco IOS XR 24.3.1

Discovery Timeline

• September 11, 2024 - CVE-2024-20489 published to NVD
• October 3, 2024 - Last updated in NVD database

Technical Details for CVE-2024-20489

Vulnerability Analysis

This vulnerability represents a plaintext storage of credentials weakness (CWE-256) combined with insufficiently protected credentials (CWE-522). The PON (Passive Optical Network) Controller component in Cisco IOS XR Software stores MongoDB database credentials in configuration files without proper encryption or access controls. This implementation flaw allows authenticated users with local access and low-level privileges to read these configuration files and extract the database credentials.

The vulnerability requires local access to the affected device, meaning an attacker must first establish a foothold on the system. However, once local access is obtained, even users with minimal privileges can access the configuration files containing the unencrypted credentials. This could lead to unauthorized access to the MongoDB database, potentially compromising the integrity and confidentiality of network management data.

Root Cause

The root cause of this vulnerability lies in the improper handling of sensitive credential data within the PON Controller configuration storage mechanism. Rather than implementing secure credential management practices—such as encrypted storage, hardware security modules, or credential vaults—the MongoDB credentials are stored in plaintext within configuration files accessible to low-privilege users. This violates fundamental security principles around credential protection and least-privilege access controls.

Attack Vector

The attack vector is local, requiring the attacker to have authenticated access to the device running Cisco IOS XR Software. The exploitation process involves:

1. An attacker gains authenticated access to the affected Cisco IOS XR device with low-privilege credentials
2. The attacker navigates to the PON Controller configuration directory
3. The attacker reads the configuration files containing the MongoDB credentials
4. The exposed credentials can then be used to access the MongoDB database directly

The vulnerability does not require user interaction and has low attack complexity, making it relatively straightforward to exploit once local access is established. The impact is limited to confidentiality—there is no direct integrity or availability impact from the credential disclosure itself, though secondary attacks using the obtained credentials could have broader implications.

Detection Methods for CVE-2024-20489

Indicators of Compromise

• Unusual file access patterns to PON Controller configuration directories by low-privilege users
• Unexpected read operations on configuration files containing database credentials
• Anomalous MongoDB authentication attempts using credentials from the affected configuration files
• Login activity from low-privilege accounts followed by configuration file access

Detection Strategies

• Implement file integrity monitoring (FIM) on PON Controller configuration directories to detect unauthorized access
• Enable and monitor audit logging for file access events on Cisco IOS XR devices
• Configure MongoDB to log authentication attempts and monitor for suspicious connection patterns
• Deploy host-based intrusion detection systems (HIDS) to identify abnormal credential access patterns

Monitoring Recommendations

• Review access logs for the PON Controller configuration files on a regular basis
• Monitor MongoDB authentication logs for connections using credentials that may have been exposed
• Set up alerts for any file access to sensitive configuration directories by non-administrative users
• Correlate local access events with subsequent database activity to identify potential credential misuse

How to Mitigate CVE-2024-20489

Immediate Actions Required

• Review and apply the latest Cisco IOS XR security patches as outlined in the vendor advisory
• Restrict file system permissions on PON Controller configuration directories to administrative users only
• Rotate MongoDB credentials immediately if exposure is suspected
• Audit all local user accounts and remove unnecessary access privileges

Patch Information

Cisco has released a security advisory addressing this vulnerability. Organizations running affected versions of Cisco IOS XR Software should consult the Cisco Security Advisory for detailed patch information and upgrade guidance. The advisory provides specific remediation steps and identifies fixed software releases.

Workarounds

• Implement strict file system access controls to limit configuration file access to only essential administrative accounts
• Configure MongoDB to use network-level access controls and firewall rules to restrict database connections
• Enable audit logging on all configuration file access and establish monitoring for anomalous patterns
• Consider implementing additional encryption layers for sensitive configuration data where operationally feasible
• Regularly rotate MongoDB credentials as part of standard security hygiene practices