Summary
An unrestricted file upload vulnerability in ILIAS QTI question import image handling can allow authenticated authors to place executable files in a web-served directory. If an attacker has question pool import rights and can submit a crafted archive, this may result in remote code execution under the web server account.
An unrestricted file upload vulnerability in ILIAS QTI question import image handling can allow authenticated authors to place executable files in a web-served directory. If an attacker has question pool import rights and can submit a crafted archive, this may result in remote code execution under the web server account.
Affected context
The vulnerability occurs in ILIAS deployments that process QTI question pool imports and handle images through the affected material security component. Risk increases when imported files can be written into a web-served directory without reliably restricting file types, enforcing safe storage, or preventing server-side execution.
The vulnerability occurs in ILIAS deployments that process QTI question pool imports and handle images through the affected material security component. Risk increases when imported files can be written into a web-served directory without reliably restricting file types, enforcing safe storage, or preventing server-side execution.
Exploit preconditions
- Attack surface: QTI question pool import and image extraction functionality
- Required access: An authenticated account with permission to import question pools
- Trigger point: Processing a crafted QTI archive during import
- Why exploitation is possible: Uploaded content can be written to a web-served image directory, where executable server-side files may be interpreted by the web server
- Attack surface: QTI question pool import and image extraction functionality
- Required access: An authenticated account with permission to import question pools
- Trigger point: Processing a crafted QTI archive during import
- Why exploitation is possible: Uploaded content can be written to a web-served image directory, where executable server-side files may be interpreted by the web server
Why this happens
The underlying flaw is insufficient validation and isolation of files extracted from an uploaded archive. The import process permits attacker-controlled content to reach a web-accessible directory without reliably enforcing an allowlist of non-executable image formats or separating uploaded assets from executable application paths. This behavior maps to CWE-434: Unrestricted Upload of File with Dangerous Type.
The underlying flaw is insufficient validation and isolation of files extracted from an uploaded archive. The import process permits attacker-controlled content to reach a web-accessible directory without reliably enforcing an allowlist of non-executable image formats or separating uploaded assets from executable application paths. This behavior maps to CWE-434: Unrestricted Upload of File with Dangerous Type.
Potential impact
- Remote code execution as the web server user may occur
- Application data and stored learning content could be accessed or modified
- Authentication material or configuration data may be exposed
- The ILIAS instance could be used to affect connected services or users
- Integrity of imported question pools and other educational content could be compromised
- Remote code execution as the web server user may occur
- Application data and stored learning content could be accessed or modified
- Authentication material or configuration data may be exposed
- The ILIAS instance could be used to affect connected services or users
- Integrity of imported question pools and other educational content could be compromised
General mitigation guidance
Mitigation generally focuses on reducing trust in imported archives and ensuring uploaded assets cannot become executable server content.
Common defensive patterns include:
- Allowing only explicitly supported image formats and validating file content rather than relying on names or extensions
- Storing uploaded and extracted files outside web-served executable paths where possible
- Applying server configuration that prevents script execution in upload and image directories
- Using generated filenames and rejecting path traversal, archive nesting, and unexpected metadata
- Enforcing least privilege for the web server and limiting its access to application and storage resources
- Applying resource limits and security review to archive extraction workflows
Mitigation generally focuses on reducing trust in imported archives and ensuring uploaded assets cannot become executable server content.
Common defensive patterns include:
- Allowing only explicitly supported image formats and validating file content rather than relying on names or extensions
- Storing uploaded and extracted files outside web-served executable paths where possible
- Applying server configuration that prevents script execution in upload and image directories
- Using generated filenames and rejecting path traversal, archive nesting, and unexpected metadata
- Enforcing least privilege for the web server and limiting its access to application and storage resources
- Applying resource limits and security review to archive extraction workflows
How teams detect issues like this
Organizations can identify similar risks through:
- Static analysis for archive extraction followed by filesystem writes without type, path, or execution checks
- Code review signals such as extension-only validation, user-controlled filenames, and writes into web roots
- Tests that verify uploaded files cannot be interpreted as server-side scripts
- Web-server policy checks ensuring asset directories disable script execution
- Monitoring for unexpected executable extensions, server configuration files, or new files in image directories
- Automated security review tools that flag dangerous upload and archive-handling patterns
Organizations can identify similar risks through:
- Static analysis for archive extraction followed by filesystem writes without type, path, or execution checks
- Code review signals such as extension-only validation, user-controlled filenames, and writes into web roots
- Tests that verify uploaded files cannot be interpreted as server-side scripts
- Web-server policy checks ensuring asset directories disable script execution
- Monitoring for unexpected executable extensions, server configuration files, or new files in image directories
- Automated security review tools that flag dangerous upload and archive-handling patterns
