CVE-2021-38945 Overview
CVE-2021-38945 is an arbitrary file upload vulnerability affecting IBM Cognos Analytics versions 11.2.1, 11.2.0, and 11.1.7. The vulnerability stems from improper content validation, allowing a remote attacker to upload arbitrary files to the affected system without authentication. This vulnerability type (CWE-434: Unrestricted Upload of File with Dangerous Type) is particularly dangerous as it can lead to remote code execution if an attacker uploads a malicious executable or web shell.
Critical Impact
Remote attackers can upload arbitrary files without authentication, potentially leading to complete system compromise, remote code execution, and unauthorized access to sensitive business intelligence data.
Affected Products
- IBM Cognos Analytics 11.2.1
- IBM Cognos Analytics 11.2.0
- IBM Cognos Analytics 11.1.7 (including Fix Packs 1-4)
- NetApp OnCommand Insight (uses IBM Cognos Analytics component)
Discovery Timeline
- 2022-06-24 - CVE-2021-38945 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2021-38945
Vulnerability Analysis
This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The flaw exists in IBM Cognos Analytics' file upload functionality, where the application fails to properly validate the content type and file extension of uploaded files. This allows attackers to bypass security controls and upload files with arbitrary content, including executable code or web shells.
The vulnerability is particularly severe because it requires no authentication to exploit. An attacker with network access to the Cognos Analytics server can exploit this vulnerability remotely without any user interaction, potentially gaining the ability to execute arbitrary code on the server with the privileges of the web application.
Root Cause
The root cause of CVE-2021-38945 is improper content validation in the file upload handling mechanism of IBM Cognos Analytics. The application does not adequately verify the type, content, or extension of files being uploaded, allowing attackers to bypass intended restrictions. This failure in input validation means that dangerous file types such as server-side scripts, executables, or web shells can be uploaded and potentially executed on the server.
Attack Vector
The attack vector for CVE-2021-38945 is network-based, requiring no privileges or user interaction. An attacker can exploit this vulnerability by:
- Identifying an IBM Cognos Analytics instance accessible over the network
- Crafting a malicious file (such as a web shell or executable) disguised or presented in a way that bypasses content validation
- Uploading the malicious file through the vulnerable file upload functionality
- Accessing or executing the uploaded file to achieve code execution or further compromise the system
The lack of authentication requirements makes this vulnerability especially dangerous for internet-facing deployments.
Detection Methods for CVE-2021-38945
Indicators of Compromise
- Unexpected files appearing in upload directories or web-accessible locations on IBM Cognos Analytics servers
- Web server logs showing unusual file upload requests, particularly with executable extensions or suspicious MIME types
- Network traffic patterns indicating attempts to access recently uploaded files with executable or script extensions
- Anomalous process execution originating from the Cognos Analytics web application context
Detection Strategies
- Monitor web server access logs for POST requests to file upload endpoints with unusual file extensions such as .jsp, .php, .aspx, or executable formats
- Implement file integrity monitoring on IBM Cognos Analytics installation directories to detect unauthorized file additions
- Deploy web application firewall (WAF) rules to detect and block file upload attempts containing suspicious content patterns
- Review application logs for failed or successful file upload events, correlating with user authentication status
Monitoring Recommendations
- Enable detailed logging for the IBM Cognos Analytics web application, capturing all file upload events and associated metadata
- Configure SIEM alerts for patterns consistent with web shell deployment or arbitrary file upload exploitation
- Establish baseline metrics for normal file upload activity to identify anomalous behavior patterns
- Monitor server processes for unexpected child processes spawned by the web server or application server
How to Mitigate CVE-2021-38945
Immediate Actions Required
- Apply the latest IBM security patches for Cognos Analytics as documented in IBM Support Document #6597241
- Restrict network access to IBM Cognos Analytics servers to trusted networks and users only
- Implement a web application firewall (WAF) with rules to block suspicious file upload attempts
- Audit existing uploaded files on affected systems for signs of malicious content
Patch Information
IBM has released security updates to address this vulnerability. Organizations should consult the official IBM Support Document #6597241 for specific patch information and upgrade instructions. NetApp customers using OnCommand Insight should refer to NetApp Security Advisory NTAP-20220729-0002 for guidance on remediation in their environment.
For detailed technical information about this vulnerability, see the IBM X-Force Vulnerability #211238.
Workarounds
- Implement strict network segmentation to limit access to Cognos Analytics servers from untrusted networks
- Deploy a reverse proxy or WAF in front of Cognos Analytics with file upload content inspection enabled
- Disable or restrict file upload functionality if not required for business operations until patches can be applied
- Configure server-side controls to prevent execution of uploaded files regardless of their extension or content type
# Example: Restrict access to Cognos Analytics using iptables
# Only allow trusted network ranges to access the application
iptables -A INPUT -p tcp --dport 9300 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 9300 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
