CVE-2026-40024: Sleuth Kit Path Traversal Vulnerability

CVE-2026-40024 Overview

The Sleuth Kit through version 4.14.0 contains a path traversal vulnerability (CWE-22) in the tsk_recover tool that allows an attacker to write files to arbitrary locations outside the intended recovery directory. This vulnerability is exploited via crafted filenames or directory paths containing path traversal sequences (e.g., /../) embedded within a malicious filesystem image.

Critical Impact

An attacker can craft a malicious filesystem image with embedded path traversal sequences in filenames that, when processed by tsk_recover, writes files outside the output directory. This can potentially achieve arbitrary code execution by overwriting shell configuration files or cron entries on the target system.

Affected Products

• The Sleuth Kit versions through 4.14.0
• Systems using tsk_recover for forensic file recovery operations
• Digital forensics workflows processing untrusted filesystem images

Discovery Timeline

• 2026-04-08 - CVE CVE-2026-40024 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-40024

Vulnerability Analysis

This path traversal vulnerability exists in the tsk_recover component of The Sleuth Kit, a widely-used open-source digital forensics toolkit. The vulnerability stems from insufficient sanitization of file paths extracted from filesystem images during the recovery process. When tsk_recover processes a malicious filesystem image containing specially crafted filenames with directory traversal sequences, it fails to properly validate and sanitize these paths before writing recovered files to the output directory.

The local attack vector requires user interaction—specifically, a user must process a malicious filesystem image with the vulnerable tsk_recover tool. However, the impact is severe as successful exploitation allows unauthorized file writes with no authentication required, potentially leading to complete system compromise.

Root Cause

The root cause of CVE-2026-40024 is the absence of input validation for special path characters within filenames extracted from filesystem images. The tsk_recover tool did not filter or reject path traversal sequences such as ../ (Unix) or ..\ (Windows) embedded in filenames, allowing attackers to escape the intended output directory boundary during file recovery operations.

Attack Vector

The attack requires local access and involves the following exploitation path:

1. An attacker crafts a malicious filesystem image (e.g., disk image, partition image) containing files with path traversal sequences embedded in their names (e.g., ../../.bashrc or ../../etc/cron.d/malicious)
2. The victim uses tsk_recover to process the malicious image, specifying an output directory for recovered files
3. The vulnerable tsk_recover tool fails to sanitize the malicious filenames and writes files outside the intended output directory
4. Depending on the targeted files (shell configurations, cron entries, SSH authorized_keys), the attacker can achieve arbitrary code execution or persistent access

The security patch introduces character filtering to prevent path traversal sequences from being processed:

// special characters we do not want to have in the name when writing out. 
#ifdef TSK_WIN32
#define TSK_IS_SPL_FILE_CHAR(x) \
    (((x) == 0x3A) || ((x) == 0x5C))
#else
#define TSK_IS_SPL_FILE_CHAR(x) \
    ((x) == 0x2F) 
#endif

Source: GitHub Commit Details

Detection Methods for CVE-2026-40024

Indicators of Compromise

• Unexpected file modifications in system configuration directories (/etc/, ~/.bashrc, ~/.profile, cron directories) following tsk_recover execution
• File write operations from tsk_recover processes targeting directories outside the specified output path
• Presence of filesystem images containing filenames with ../ or ..\ path traversal sequences

Detection Strategies

• Monitor tsk_recover process file operations for writes outside designated output directories using file integrity monitoring (FIM) tools
• Implement system call auditing to detect suspicious path traversal patterns in file operations originating from forensic tools
• Deploy endpoint detection rules to alert on tsk_recover writing to sensitive system paths such as /etc/cron.d/, /etc/profile.d/, or user shell configuration files

Monitoring Recommendations

• Enable audit logging for file creation and modification events in critical system directories when forensic operations are performed
• Implement sandbox environments for processing untrusted filesystem images to contain potential exploitation attempts
• Utilize SentinelOne's Behavioral AI to detect anomalous file write patterns from forensic utilities targeting system configuration files

How to Mitigate CVE-2026-40024

Immediate Actions Required

• Update The Sleuth Kit to a patched version that includes the security fix (commit a3f96b3bc36a8bb1a00c297f77110d4a6e7dd31b)
• Audit recent tsk_recover operations to identify any potential exploitation attempts or unauthorized file writes
• Restrict execution of tsk_recover to dedicated forensic workstations with limited network access and restricted write permissions

Patch Information

The vulnerability has been addressed in a security patch available through the official Sleuth Kit repository. The fix introduces special character filtering in tools/autotools/tsk_recover.cpp to sanitize path traversal symbols from export paths during file recovery operations. Organizations should apply the patch from the GitHub commit or update to a version containing this fix.

For additional technical details, refer to the VulnCheck Security Advisory.

Workarounds

• Process untrusted filesystem images in isolated virtual machines or containers with no access to critical system paths
• Run tsk_recover with restricted permissions using a dedicated low-privilege user account that cannot write to sensitive directories
• Pre-validate filesystem images by scanning for path traversal sequences in filenames before processing with tsk_recover

# Run tsk_recover in a restricted directory with limited permissions
mkdir -p /tmp/tsk_recovery_sandbox
chmod 700 /tmp/tsk_recovery_sandbox
sudo -u forensic_user tsk_recover -e /path/to/image.dd /tmp/tsk_recovery_sandbox/