Summary
Zuke prior to 1.51.0 can introduce command injection when Windows .cmd or .bat shims are launched through cmd /c using command lines assembled with C-runtime quoting rules. If attacker-influenced text contains unquoted shell metacharacters such as &, |, or ^, an attacker may execute an additional command in the build context and access available credentials.
Zuke prior to 1.51.0 can introduce command injection when Windows .cmd or .bat shims are launched through cmd /c using command lines assembled with C-runtime quoting rules. If attacker-influenced text contains unquoted shell metacharacters such as &, |, or ^, an attacker may execute an additional command in the build context and access available credentials.
Affected context
The issue occurs in Zuke's Windows-specific tool-launching path when a build resolves an executable shim from node_modules/.bin and incorporates attacker-influenced text into the command line. The risk depends on Windows shell interpretation, the use of .cmd or .bat shims, and the permissions and credentials available to the build process. POSIX platforms are not affected by this behavior.
The issue occurs in Zuke's Windows-specific tool-launching path when a build resolves an executable shim from node_modules/.bin and incorporates attacker-influenced text into the command line. The risk depends on Windows shell interpretation, the use of .cmd or .bat shims, and the permissions and credentials available to the build process. POSIX platforms are not affected by this behavior.
Exploit preconditions
- Attack surface: Zuke build execution on Windows
- Required access: Ability to influence text passed into a resolved tool invocation or build configuration
- Trigger point: Launch of a resolved
.cmdor.batshim throughcmd /c - Why exploitation is possible: C-runtime quoting does not reliably prevent
cmd.exefrom reparsing unquoted shell metacharacters, allowing command separators or control operators to alter execution
- Attack surface: Zuke build execution on Windows
- Required access: Ability to influence text passed into a resolved tool invocation or build configuration
- Trigger point: Launch of a resolved
.cmdor.batshim throughcmd /c - Why exploitation is possible: C-runtime quoting does not reliably prevent
cmd.exefrom reparsing unquoted shell metacharacters, allowing command separators or control operators to alter execution
Why this happens
The vulnerable pattern combines an indirectly executed Windows command interpreter with command-line construction rules that do not preserve argument boundaries through shell reparsing. When attacker-controlled text reaches the assembled command line, characters interpreted by cmd.exe may change the command structure and cause additional commands to run. This behavior maps to CWE-78: Improper Neutralization of Special Elements used in an OS Command, because untrusted input is allowed to influence shell command interpretation.
The vulnerable pattern combines an indirectly executed Windows command interpreter with command-line construction rules that do not preserve argument boundaries through shell reparsing. When attacker-controlled text reaches the assembled command line, characters interpreted by cmd.exe may change the command structure and cause additional commands to run. This behavior maps to CWE-78: Improper Neutralization of Special Elements used in an OS Command, because untrusted input is allowed to influence shell command interpretation.
Potential impact
- An attacker could execute arbitrary commands in the build context.
- Build credentials, tokens, or other environment secrets may be exposed.
- Source code, generated artifacts, or dependencies could be modified.
- CI runners or developer workstations could be compromised.
- A compromised build may produce tampered or malicious release artifacts.
- An attacker could execute arbitrary commands in the build context.
- Build credentials, tokens, or other environment secrets may be exposed.
- Source code, generated artifacts, or dependencies could be modified.
- CI runners or developer workstations could be compromised.
- A compromised build may produce tampered or malicious release artifacts.
General mitigation guidance
Mitigation generally focuses on avoiding shell interpretation and preserving arguments as structured data.
Common defensive patterns include:
- Prefer direct process-spawn APIs that do not invoke
cmd.exewhen launching tools. - Resolve executables to trusted paths and treat tool-selection data as untrusted.
- Apply strict allowlists and validation to values that can reach build command arguments.
- Use argument-array interfaces rather than concatenated command strings.
- Minimize build credentials and permissions, and isolate builds from sensitive resources.
- Apply secure-by-default runner policies that restrict shell access and secret exposure.
- Keep build dependencies and execution environments maintained through the organization's normal update process.
Mitigation generally focuses on avoiding shell interpretation and preserving arguments as structured data.
Common defensive patterns include:
- Prefer direct process-spawn APIs that do not invoke
cmd.exewhen launching tools. - Resolve executables to trusted paths and treat tool-selection data as untrusted.
- Apply strict allowlists and validation to values that can reach build command arguments.
- Use argument-array interfaces rather than concatenated command strings.
- Minimize build credentials and permissions, and isolate builds from sensitive resources.
- Apply secure-by-default runner policies that restrict shell access and secret exposure.
- Keep build dependencies and execution environments maintained through the organization's normal update process.
How teams detect issues like this
Detection can combine source analysis, review, and runtime policy controls:
- Search for Windows process launches that prepend
cmd /cor otherwise invoke shell interpreters. - Flag string concatenation or interpolation used to construct command lines from build inputs.
- Review handling of
.cmdand.batshims, especially where arguments originate from configuration, dependencies, or generated metadata. - Use static analysis and automated code review rules for shell-command construction and missing argument separation.
- Monitor build processes for unexpected child commands, shell metacharacters, or execution outside approved tool paths.
- Enforce CI policies that limit shell invocation, credential scope, and network access for build jobs.
Detection can combine source analysis, review, and runtime policy controls:
- Search for Windows process launches that prepend
cmd /cor otherwise invoke shell interpreters. - Flag string concatenation or interpolation used to construct command lines from build inputs.
- Review handling of
.cmdand.batshims, especially where arguments originate from configuration, dependencies, or generated metadata. - Use static analysis and automated code review rules for shell-command construction and missing argument separation.
- Monitor build processes for unexpected child commands, shell metacharacters, or execution outside approved tool paths.
- Enforce CI policies that limit shell invocation, credential scope, and network access for build jobs.
