Summary
easy-pdf-merge may allow OS command injection when shell metacharacters are included in source paths, the destination path, or the maxHeap option. If attacker-controlled values reach the package's child_process.exec() call, commands could run with the privileges of the Node.js process.
easy-pdf-merge may allow OS command injection when shell metacharacters are included in source paths, the destination path, or the maxHeap option. If attacker-controlled values reach the package's child_process.exec() call, commands could run with the privileges of the Node.js process.
Affected context
The vulnerability occurs in applications using affected easy-pdf-merge releases to construct PDF merge commands from user-controlled or insufficiently trusted values. Risk is higher when file names, output paths, or memory-related options can be influenced by external users and are passed to a shell without strict validation or safe argument handling.
The vulnerability occurs in applications using affected easy-pdf-merge releases to construct PDF merge commands from user-controlled or insufficiently trusted values. Risk is higher when file names, output paths, or memory-related options can be influenced by external users and are passed to a shell without strict validation or safe argument handling.
Exploit preconditions
- Attack surface: Application functionality that invokes easy-pdf-merge for PDF merging
- Required access: Ability to influence a source path, destination path, or maxHeap option
- Trigger point: Construction and execution of the merge command
- Why exploitation is possible: Input reaches
child_process.exec(), which interprets shell metacharacters through a command shell
- Attack surface: Application functionality that invokes easy-pdf-merge for PDF merging
- Required access: Ability to influence a source path, destination path, or maxHeap option
- Trigger point: Construction and execution of the merge command
- Why exploitation is possible: Input reaches
child_process.exec(), which interprets shell metacharacters through a command shell
Why this happens
The underlying bug is the use of a shell-based process execution API with values that may contain attacker-controlled file paths or options. Characters such as command separators, command substitutions, backticks, or quotation marks can alter the intended command structure instead of remaining data. This behavior maps to CWE-78: Improper Neutralization of Special Elements used in an OS Command, commonly known as OS command injection.
The underlying bug is the use of a shell-based process execution API with values that may contain attacker-controlled file paths or options. Characters such as command separators, command substitutions, backticks, or quotation marks can alter the intended command structure instead of remaining data. This behavior maps to CWE-78: Improper Neutralization of Special Elements used in an OS Command, commonly known as OS command injection.
Potential impact
- An attacker may execute arbitrary operating-system commands
- The Node.js process could be compromised with its runtime privileges
- Sensitive files or environment variables could be read or modified
- The host or container could be used for further unauthorized activity
- Application availability or generated PDF processing could be disrupted
- An attacker may execute arbitrary operating-system commands
- The Node.js process could be compromised with its runtime privileges
- Sensitive files or environment variables could be read or modified
- The host or container could be used for further unauthorized activity
- Application availability or generated PDF processing could be disrupted
General mitigation guidance
Mitigation generally focuses on removing shell interpretation from process execution and reducing trust in command inputs.
Common defensive patterns include:
- Prefer non-shell process APIs that accept executable names and structured argument arrays
- Apply strict allowlists and canonicalization to source and destination paths
- Validate numeric options such as memory limits against bounded formats and ranges
- Avoid building command strings through concatenation or interpolation
- Restrict the Node.js process to a dedicated, least-privileged account or container
- Limit filesystem access and isolate temporary PDF-processing directories
- Treat user-supplied file names and options as data rather than executable command fragments
Mitigation generally focuses on removing shell interpretation from process execution and reducing trust in command inputs.
Common defensive patterns include:
- Prefer non-shell process APIs that accept executable names and structured argument arrays
- Apply strict allowlists and canonicalization to source and destination paths
- Validate numeric options such as memory limits against bounded formats and ranges
- Avoid building command strings through concatenation or interpolation
- Restrict the Node.js process to a dedicated, least-privileged account or container
- Limit filesystem access and isolate temporary PDF-processing directories
- Treat user-supplied file names and options as data rather than executable command fragments
How teams detect issues like this
Organizations can look for this vulnerability through:
- Static analysis rules identifying
child_process.exec()or equivalent shell APIs fed by request, file, or option values - Code review checks for command construction using string concatenation, interpolation, or quoting as the primary defense
- Dependency and call-graph analysis showing whether PDF-processing inputs originate outside a trusted boundary
- Runtime monitoring for unexpected child processes, shell interpreters, or command separators in process arguments
- Policy enforcement that restricts shell-based process execution and requires structured argument APIs
Automated security review tools may help identify these patterns during development.
Organizations can look for this vulnerability through:
- Static analysis rules identifying
child_process.exec()or equivalent shell APIs fed by request, file, or option values - Code review checks for command construction using string concatenation, interpolation, or quoting as the primary defense
- Dependency and call-graph analysis showing whether PDF-processing inputs originate outside a trusted boundary
- Runtime monitoring for unexpected child processes, shell interpreters, or command separators in process arguments
- Policy enforcement that restricts shell-based process execution and requires structured argument APIs
Automated security review tools may help identify these patterns during development.
