CVE-2025-20344: Cisco Nexus Dashboard Path Traversal

CVE-2025-20344 Overview

Cisco disclosed CVE-2025-20344, a path traversal vulnerability in the backup restore functionality of Cisco Nexus Dashboard. The flaw allows an authenticated remote attacker with valid Administrator credentials to traverse directories by restoring a crafted backup file. Successful exploitation grants root privileges on the underlying shell of the affected device.

The vulnerability is tracked under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory). It affects Cisco Nexus Dashboard deployments managing data center fabrics, which makes the post-exploitation impact significant for network operators.

Critical Impact
An authenticated administrator can escalate from application-layer privileges to root on the host shell, breaking the security boundary between the management plane and the underlying operating system.

Affected Products

Cisco Nexus Dashboard (all versions prior to the fixed release listed in the Cisco advisory)
Deployments using the backup and restore feature
Both physical and virtual Nexus Dashboard appliances

Discovery Timeline

2025-08-27 - CVE-2025-20344 published to the National Vulnerability Database
2025-09-08 - Last updated in the NVD database

Technical Details for CVE-2025-20344

Vulnerability Analysis

The vulnerability resides in how Cisco Nexus Dashboard processes backup archives during a restore operation. The restore routine extracts archive contents without sufficiently validating file paths inside the archive. An attacker who packages files with traversal sequences such as ../ can write content outside the intended restore directory.

Because the restore process runs with elevated privileges on the appliance, attacker-controlled files can land in sensitive locations on the underlying shell. Replacing or planting binaries, init scripts, or configuration files in those locations yields code execution as root. The flaw transforms an Administrator-level application action into full host compromise.

The attack vector is network-based against the management interface, but exploitation requires valid Administrator credentials. This narrows the threat to insiders, credential-theft scenarios, or post-exploitation pivots from a compromised admin workstation.

Root Cause

The root cause is insufficient validation of backup file contents during restore. The application trusts archive metadata, including embedded file paths, and writes extracted files to disk without canonicalizing paths or enforcing a chroot-style boundary. This is a classic Zip Slip-style path traversal pattern applied to a restore workflow.

Attack Vector

An attacker authenticates to the Nexus Dashboard web interface or API with Administrator credentials. The attacker uploads a malicious backup archive containing entries with traversal sequences pointing to writable system paths. When the restore operation processes the archive, the crafted entries are written outside the intended directory. On the next service execution or scheduled task, the attacker's payload runs as root.

No verified public proof-of-concept code is available. See the Cisco Security Advisory for vendor-confirmed technical details.

Detection Methods for CVE-2025-20344

Indicators of Compromise

Backup restore events initiated outside of normal change windows or by accounts that do not normally perform restores
Unexpected files appearing in system directories such as /etc, /usr/local/bin, or service init paths following a restore operation
New or modified cron jobs, systemd units, or shell profile scripts on the Nexus Dashboard appliance after a restore
Administrator session activity from unusual source IPs preceding a restore operation

Detection Strategies

Audit Nexus Dashboard logs for restore API calls and correlate against authorized change tickets
Compare file system baselines of the appliance before and after restore operations to surface writes outside the expected restore directory
Alert on any post-restore creation or modification of files owned by root in directories not referenced by the backup schema

Monitoring Recommendations

Forward Nexus Dashboard audit logs to a centralized SIEM and build identifications for backup upload and restore actions
Monitor Administrator account usage with strict alerting on credential reuse, MFA bypass attempts, and anomalous geolocation
Track integrity of critical system paths on the appliance using file integrity monitoring where supported

How to Mitigate CVE-2025-20344

Immediate Actions Required

Apply the fixed software release identified in the Cisco Security Advisory cisco-sa-nd-ptrs-XU2Fm2Wb
Rotate all Nexus Dashboard Administrator credentials and enforce multi-factor authentication on management access
Restrict network access to the Nexus Dashboard management interface to a dedicated administrative network
Review recent backup restore activity for unauthorized or unexplained operations

Patch Information

Cisco has published fixed releases for Cisco Nexus Dashboard. Refer to the Cisco Security Advisory for the specific fixed version matrix and upgrade guidance. There are no documented vendor workarounds; upgrading is the supported remediation.

Workarounds

Limit the number of accounts holding the Administrator role and apply least-privilege principles to backup and restore operations
Source backup files only from trusted, integrity-verified storage and validate hashes before any restore
Disable or tightly control external upload paths used to stage backup archives until the patch is applied