CVE-2024-20449: Cisco NDFC Path Traversal Vulnerability

CVE-2024-20449 Overview

CVE-2024-20449 is a path traversal vulnerability in Cisco Nexus Dashboard Fabric Controller (NDFC) that enables arbitrary code execution. An authenticated, remote attacker with low privileges can upload malicious files via Secure Copy Protocol (SCP) and execute code with root privileges inside a specific container. The flaw stems from improper path validation during SCP file handling. Cisco assigned the vulnerability a CVSS 3.1 score of 8.8 and mapped it to CWE-22 and CWE-23. The EPSS score is 0.938% at the 57th percentile as of August 2026.

Critical Impact
Authenticated attackers can achieve root-level arbitrary code execution inside an NDFC container by abusing SCP path traversal, compromising fabric management integrity.

Affected Products

Cisco Nexus Dashboard Fabric Controller (NDFC)
NDFC deployments managing LAN, SAN, and IP Fabric for Media
Cisco Nexus Dashboard clusters hosting the NDFC service

Discovery Timeline

2024-10-02 - CVE-2024-20449 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-20449

Vulnerability Analysis

The vulnerability lives in the SCP handling logic of Cisco Nexus Dashboard Fabric Controller. NDFC accepts file uploads over SCP as part of its fabric management workflows. The application fails to sanitize path components in SCP requests, allowing an authenticated user to reference locations outside the intended upload directory.

A successful exploit places attacker-controlled files at arbitrary paths inside a target container. Because the receiving process runs as root, the attacker can overwrite executable scripts, configuration files, or startup hooks that are later invoked with elevated privileges. This converts a file upload primitive into arbitrary code execution.

The issue requires authentication and low privileges but no user interaction. The attack vector is the network-exposed SCP interface, and impact spans confidentiality, integrity, and availability at the container level.

Root Cause

The root cause is improper limitation of a pathname to a restricted directory [CWE-22] combined with relative path traversal handling [CWE-23]. The SCP handler does not canonicalize or validate destination paths against an allowlisted base directory, so ../ sequences and absolute paths escape the intended sandbox.

Attack Vector

An attacker authenticates to NDFC with any account that has SCP upload rights. The attacker then issues an SCP transfer whose destination path contains traversal sequences that resolve to sensitive locations within the container filesystem. Once a file lands at a privileged path, the attacker triggers or waits for its execution under the root context.

No verified public exploit code is available. See the Cisco Security Advisory for vendor-supplied technical detail.

Detection Methods for CVE-2024-20449

Indicators of Compromise

SCP sessions to NDFC management interfaces containing ../ sequences or absolute path arguments in the destination filename.
Unexpected files appearing in NDFC container directories outside the documented upload paths.
New or modified executables, cron entries, or startup scripts inside NDFC service containers that were not deployed by change management.
Root-owned processes spawning from non-standard binaries within NDFC containers.

Detection Strategies

Inspect SSH and SCP audit logs on the Nexus Dashboard for authenticated file transfers referencing non-standard destinations.
Baseline the NDFC container filesystem and alert on writes outside expected upload directories.
Correlate authentication events for low-privileged NDFC users with subsequent SCP transfer activity and container process creation.

Monitoring Recommendations

Forward Nexus Dashboard audit logs, SSH daemon logs, and container runtime events to a central SIEM for correlation.
Enable file integrity monitoring on NDFC container mount points and service binaries.
Alert on any privilege escalation or root-owned process launches that were not initiated by the NDFC service accounts.

How to Mitigate CVE-2024-20449

Immediate Actions Required

Apply the fixed NDFC release identified in the Cisco Security Advisory cisco-sa-ndfc-ptrce-BUSHLbp.
Audit and reduce NDFC user accounts that hold SCP upload permissions.
Rotate credentials for all NDFC administrative and API users after patching.
Restrict network access to the Nexus Dashboard management plane to trusted operator subnets only.

Patch Information

Cisco published fixed software versions in the security advisory cisco-sa-ndfc-ptrce-BUSHLbp. Administrators should consult the advisory for the exact fixed release matching their deployment and follow Cisco's upgrade procedure for Nexus Dashboard and NDFC services.

Workarounds

No official workaround is listed by Cisco; upgrading to a fixed release is the supported remediation path.
Where immediate patching is not possible, isolate the Nexus Dashboard management network with strict access control lists limiting SSH and SCP to a jump host.
Enforce least privilege on NDFC role assignments so that only vetted operators retain file transfer capabilities.

bash

# Verify running NDFC version and compare against the fixed release in the advisory
kubectl -n cisco-ndfc get pods -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'

# Restrict management-plane SSH/SCP access at the perimeter
iptables -A INPUT -p tcp --dport 22 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j DROP