CVE-2025-13044: IBM Concert Privilege Escalation Flaw

CVE-2025-13044 Overview

IBM Concert versions 1.0.0 through 2.2.0 contain a vulnerability where the application creates temporary files with predictable names. This predictable naming pattern allows local users to exploit a symlink attack to overwrite arbitrary files on the system, potentially leading to data corruption, denial of service, or in some scenarios, privilege escalation through the manipulation of critical system files.

Critical Impact

Local attackers can leverage predictable temporary file names to create symbolic links that redirect file operations, enabling arbitrary file overwrites with the privileges of the IBM Concert process.

Affected Products

• IBM Concert 1.0.0
• IBM Concert versions through 2.2.0
• All IBM Concert deployments using vulnerable temporary file handling

Discovery Timeline

• April 7, 2026 - CVE-2025-13044 published to NVD
• April 7, 2026 - Last updated in NVD database

Technical Details for CVE-2025-13044

Vulnerability Analysis

This vulnerability is classified under CWE-340 (Generation of Predictable Numbers or Identifiers). IBM Concert's temporary file creation mechanism uses a predictable naming convention that allows attackers to anticipate the exact filename that will be created during application operations. When an attacker can predict the temporary filename, they can preemptively create a symbolic link at that location pointing to a target file they wish to overwrite.

The attack exploits a race condition between the time IBM Concert checks for file existence and when it actually writes to the file. By winning this race, an attacker can redirect the write operation to any file accessible by the Concert process, potentially overwriting critical configuration files, application data, or system files.

Root Cause

The root cause is the use of predictable patterns for generating temporary filenames in IBM Concert. Instead of using cryptographically secure random identifiers or properly isolated temporary directories with exclusive access controls, the application generates filenames that local users can easily guess or enumerate. This violates secure coding practices for temporary file handling.

Attack Vector

This is a local attack vector requiring the attacker to have local access to the system where IBM Concert is installed. The attack follows this general pattern:

1. The attacker monitors or predicts the temporary file naming pattern used by IBM Concert
2. Before the application creates its temporary file, the attacker creates a symbolic link with the predicted filename
3. The symlink points to a target file the attacker wishes to overwrite (e.g., /etc/passwd, application configuration files, or log files)
4. When IBM Concert writes to what it believes is a temporary file, the data is instead written to the target file via the symlink
5. The target file is overwritten with the content intended for the temporary file

This type of Time-of-Check Time-of-Use (TOCTOU) vulnerability can result in integrity compromise of arbitrary files accessible by the running process.

Detection Methods for CVE-2025-13044

Indicators of Compromise

• Unexpected symbolic links appearing in temporary directories used by IBM Concert
• Modified system or configuration files with timestamps correlating to IBM Concert operations
• Unusual file system activity in /tmp or application-specific temporary directories
• Evidence of symlink creation by unauthorized users in monitored directories

Detection Strategies

• Monitor file system operations in temporary directories for symlink creation patterns
• Implement file integrity monitoring (FIM) on critical system and application configuration files
• Alert on unexpected permission changes or ownership modifications to protected files
• Deploy endpoint detection rules that correlate symlink creation with subsequent file write operations

Monitoring Recommendations

• Configure audit logging for file operations in directories used by IBM Concert for temporary files
• Implement real-time monitoring for symbolic link creation in system temporary directories
• Enable SentinelOne behavioral AI to detect TOCTOU exploitation patterns
• Review application logs for errors related to file access that may indicate exploitation attempts

How to Mitigate CVE-2025-13044

Immediate Actions Required

• Upgrade IBM Concert to a patched version as specified in the IBM security advisory
• Restrict local user access to systems running IBM Concert to trusted administrators only
• Configure dedicated temporary directories with strict permissions for IBM Concert operations
• Enable enhanced monitoring on systems running vulnerable IBM Concert versions until patches are applied

Patch Information

IBM has released a security advisory addressing this vulnerability. Organizations should consult the IBM Support Page for detailed patch information and upgrade instructions for IBM Concert. The patch addresses the predictable temporary file naming issue by implementing secure random filename generation.

Workarounds

• Create a dedicated temporary directory for IBM Concert with permissions set to 0700 owned by the service account
• Mount the temporary directory with the noexec and nosuid options to limit exploitation potential
• Implement mandatory access controls (SELinux/AppArmor) to restrict which files the IBM Concert process can write to
• Use system hardening tools to monitor and prevent symlink attacks in temporary directories

# Configuration example - Create secure temporary directory for IBM Concert
mkdir -p /var/lib/concert/tmp
chown concert:concert /var/lib/concert/tmp
chmod 0700 /var/lib/concert/tmp

# Set TMPDIR environment variable for IBM Concert service
export TMPDIR=/var/lib/concert/tmp