CVE-2025-36081: IBM Concert Log Injection Vulnerability

CVE-2025-36081 Overview

CVE-2025-36081 affects IBM Concert Software versions 1.0.0 through 2.0.0. The vulnerability allows a remote unauthenticated user to modify system logs due to improper neutralization of log input [CWE-117]. Attackers can inject arbitrary content into log files by sending crafted input over the network. This can corrupt audit trails, forge log entries, and hinder incident response and forensic investigations. The flaw does not require privileges or user interaction, and is exploitable over the network with low attack complexity.

Critical Impact
Attackers can forge or manipulate system log entries in IBM Concert, undermining audit integrity and complicating incident detection and forensic analysis.

Affected Products

IBM Concert Software 1.0.0 through 2.0.0
Deployments running on Linux kernel-based hosts
Environments ingesting IBM Concert logs into centralized SIEM systems

Discovery Timeline

2025-10-28 - CVE-2025-36081 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-36081

Vulnerability Analysis

The vulnerability stems from improper neutralization of user-controllable input written to log files in IBM Concert Software. When the application processes input destined for log entries, it fails to sanitize control characters such as carriage returns, line feeds, and terminal escape sequences. An attacker can submit crafted values that break out of the intended log line and insert additional forged entries.

Log injection attacks classified under [CWE-117] target the integrity of logging pipelines rather than confidentiality or availability. Successful exploitation does not grant code execution but degrades the trustworthiness of records used for auditing, alerting, and compliance. The EPSS score of 0.216% reflects a low probability of imminent exploitation, but the network-accessible attack path warrants remediation.

Root Cause

The root cause is missing output encoding on log write operations. IBM Concert passes user-supplied strings directly into log statements without stripping or escaping newline characters (\n, \r) and other control sequences. This violates secure logging practices requiring neutralization before persistence.

Attack Vector

An unauthenticated remote attacker sends requests containing embedded newline characters and forged log fields to any IBM Concert endpoint that records request data. The injected content is written verbatim to the log stream, producing entries that appear legitimate to downstream parsers. Attackers can use this to mask malicious activity, frame legitimate users, or inject payloads that exploit log viewers.

No verified exploit code is currently public. The vulnerability is described in prose only; refer to the IBM Support Page for vendor technical details.

Detection Methods for CVE-2025-36081

Indicators of Compromise

Log entries containing embedded CRLF sequences, unexpected timestamps, or duplicated field structures within a single record
Multiple log lines originating from a single HTTP request or API call
Log entries with mismatched source IP, user identifiers, or session tokens that do not correlate with authentication events
Presence of terminal escape sequences or non-printable characters in IBM Concert log files

Detection Strategies

Parse IBM Concert logs and flag records containing raw \r\n, %0d%0a, or Unicode line separators in user-controlled fields
Correlate authentication events with logged user identifiers to detect forged actor attribution
Apply schema validation on ingested log records to reject entries with malformed field counts

Monitoring Recommendations

Forward IBM Concert logs to a centralized SIEM with structured parsing to detect anomalies at ingestion
Enable file integrity monitoring on log directories to identify tampering attempts
Alert on inbound HTTP requests to IBM Concert containing encoded newline characters in parameters or headers

How to Mitigate CVE-2025-36081

Immediate Actions Required

Upgrade IBM Concert Software to a fixed release as published on the IBM Support Page
Restrict network access to IBM Concert management interfaces to trusted administrative networks
Review historical log data for signs of forged entries prior to patching

Patch Information

IBM has published remediation guidance for CVE-2025-36081. Administrators should consult the IBM Support Page for the fixed version and upgrade instructions covering IBM Concert 1.0.0 through 2.0.0.

Workarounds

Deploy a reverse proxy or web application firewall rule to strip CRLF and control characters from inbound request parameters and headers
Configure downstream log parsers to reject or escape records containing embedded newline sequences
Limit log viewer access and use tools that render control characters as literal escapes rather than interpreting them

bash

# Example WAF rule pattern to block CRLF injection in request parameters
# ModSecurity example
SecRule ARGS|REQUEST_HEADERS "@rx (?:\r\n|%0d%0a|%0D%0A)" \
    "id:1003601,phase:2,deny,status:400,log,\
    msg:'CRLF injection attempt targeting IBM Concert logging'"