CVE-2026-79939: Dell PowerProtect Symlink Privilege Escalation

CVE-2026-79939 Overview

Dell PowerProtect Cyber Recovery contains a UNIX symbolic link (symlink) following vulnerability in versions prior to 20.3. A low-privileged local attacker can exploit this flaw to achieve script injection. The vulnerability is classified under CWE-61 (UNIX Symbolic Link Following) and affects the integrity of the recovery platform. Successful exploitation lets an attacker manipulate files that the application accesses through unsafe symlink resolution, resulting in injected script execution within the application's context.

Critical Impact
A low-privileged local attacker can leverage symlink following to inject scripts into Dell PowerProtect Cyber Recovery, compromising integrity of the cyber recovery vault.

Affected Products

Dell PowerProtect Cyber Recovery versions prior to 20.3

Discovery Timeline

2026-08-26 - CVE-2026-79939 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-79939

Vulnerability Analysis

The flaw resides in how Dell PowerProtect Cyber Recovery handles file operations that traverse symbolic links. When the application performs privileged file writes or reads on paths controlled by a lower-privileged user, an attacker can substitute a target path with a symlink pointing to a sensitive file. The application follows the link during operations, resulting in script injection into files that are later executed or interpreted by the platform.

Because exploitation requires local access and existing low privileges, the attack surface is limited to users who can already authenticate to the underlying host. The primary consequence is integrity loss, allowing manipulation of scripts consumed by the recovery workflow.

Root Cause

The root cause is improper validation of file paths before performing file system operations [CWE-61]. The application does not verify whether a target path is a symbolic link, nor does it perform operations relative to a trusted file descriptor. This lets a local attacker plant symlinks that redirect writes to attacker-chosen destinations.

Attack Vector

Exploitation requires local access with low privileges. The attacker places a symbolic link in a predictable path used by PowerProtect Cyber Recovery. When the application processes the path with higher privileges, the symlink is followed and script content is written to or read from an unintended location. The injected script is then interpreted during subsequent recovery operations.

No verified public exploit code is available. See the Dell Security Update DSA-2026-370 for vendor-provided technical details.

Detection Methods for CVE-2026-79939

Indicators of Compromise

Unexpected symbolic links inside directories used by Dell PowerProtect Cyber Recovery for temporary files, logs, or configuration.
Modifications to shell scripts or configuration files owned by the PowerProtect service account outside of scheduled maintenance windows.
Log entries showing PowerProtect processes writing to paths outside their normal working directories.

Detection Strategies

Audit file creation and symlink() system calls in PowerProtect application directories using Linux auditd rules.
Compare cryptographic hashes of PowerProtect scripts and configuration files against known-good baselines.
Alert on any non-administrative user creating symlinks that target files owned by the PowerProtect service account.

Monitoring Recommendations

Enable file integrity monitoring on all Dell PowerProtect Cyber Recovery installation and runtime directories.
Forward local host telemetry to a centralized log platform and retain shell history for accounts with local access to the vault host.
Review privileged process activity for anomalous file operations following user logins.

How to Mitigate CVE-2026-79939

Immediate Actions Required

Upgrade Dell PowerProtect Cyber Recovery to version 20.3 or later as specified in the vendor advisory.
Restrict local shell access to the Cyber Recovery host to a minimal set of administrators.
Review existing files and symlinks in PowerProtect working directories for unauthorized changes prior to patching.

Patch Information

Dell has released a fixed version in Dell PowerProtect Cyber Recovery 20.3. Refer to the Dell Security Update DSA-2026-370 for download instructions and upgrade guidance.

Workarounds

Limit interactive and SSH access to the Cyber Recovery vault host to trusted administrators only.
Enforce strict file system permissions so that only the service account can write to PowerProtect runtime directories.
Enable auditd rules to log symlink, symlinkat, and openat calls targeting PowerProtect paths until the patch is applied.

bash

# Example auditd rule to monitor symlink creation in PowerProtect directories
-a always,exit -F arch=b64 -S symlink -S symlinkat -F dir=/opt/dell/cyberrecovery -k ppcr_symlink
-a always,exit -F arch=b64 -S openat -F dir=/opt/dell/cyberrecovery -F success=1 -k ppcr_open