Summary
Grav Git Sync contains a command injection vulnerability in author profile fields used during Git commit operations. An authenticated content editor may be able to execute operating-system commands as the web-server account when author mode is enabled and supplied profile values reach a shell command.
Grav Git Sync contains a command injection vulnerability in author profile fields used during Git commit operations. An authenticated content editor may be able to execute operating-system commands as the web-server account when author mode is enabled and supplied profile values reach a shell command.
Affected context
The issue may occur in Grav Git Sync deployments where authenticated content editors can control username, full-name, or email profile fields and where gravuser or gravfull author mode is enabled. Risk depends on those values being incorporated into a Git command through a shell-executing interface without adequate separation between data and command syntax.
The issue may occur in Grav Git Sync deployments where authenticated content editors can control username, full-name, or email profile fields and where gravuser or gravfull author mode is enabled. Risk depends on those values being incorporated into a Git command through a shell-executing interface without adequate separation between data and command syntax.
Exploit preconditions
- Attack surface: Grav Git Sync author profile and Git commit handling
- Required access: Authenticated content-editor permissions capable of changing relevant profile fields
- Trigger point: A Git commit operation that uses the configured author identity
- Required configuration:
gravuserorgravfullauthor mode must be enabled - Why exploitation is possible: User-controlled author fields reach a shell command executed through PHP
exec()without sufficient command and argument isolation
- Attack surface: Grav Git Sync author profile and Git commit handling
- Required access: Authenticated content-editor permissions capable of changing relevant profile fields
- Trigger point: A Git commit operation that uses the configured author identity
- Required configuration:
gravuserorgravfullauthor mode must be enabled - Why exploitation is possible: User-controlled author fields reach a shell command executed through PHP
exec()without sufficient command and argument isolation
Why this happens
The underlying bug is the construction of an operating-system command from attacker-influenced profile data and its execution through a shell-capable API. Special shell syntax in a username, full name, or email can therefore be interpreted as command structure rather than treated solely as data. This behavior maps to CWE-78, Improper Neutralization of Special Elements used in an OS Command.
The underlying bug is the construction of an operating-system command from attacker-influenced profile data and its execution through a shell-capable API. Special shell syntax in a username, full name, or email can therefore be interpreted as command structure rather than treated solely as data. This behavior maps to CWE-78, Improper Neutralization of Special Elements used in an OS Command.
Potential impact
- An attacker may execute commands with the privileges of the web-server account.
- The application or its stored content could be modified or compromised.
- Repository data, credentials, or other locally accessible secrets could be exposed.
- The attacker could tamper with Git history or synchronized content.
- The compromised account could be used for further lateral movement, depending on deployment permissions.
- An attacker may execute commands with the privileges of the web-server account.
- The application or its stored content could be modified or compromised.
- Repository data, credentials, or other locally accessible secrets could be exposed.
- The attacker could tamper with Git history or synchronized content.
- The compromised account could be used for further lateral movement, depending on deployment permissions.
General mitigation guidance
Mitigation generally focuses on preventing user-controlled values from being
interpreted by a shell.
Common defensive patterns include:
- Prefer native process APIs that pass executable arguments separately rather than invoking a shell.
- Treat profile fields as untrusted data and apply strict, context-appropriate validation.
- Use allowlisted character sets and bounded lengths for Git author identity fields where compatible with application requirements.
- Avoid dynamic command-string construction and ensure argument escaping is not the sole security boundary.
- Restrict the web-server account's filesystem, repository, and process privileges.
- Limit which authenticated roles can alter author identity fields or trigger synchronization operations.
- Keep sensitive credentials and writable repositories outside unnecessarily privileged application contexts.
Mitigation generally focuses on preventing user-controlled values from being
interpreted by a shell.
Common defensive patterns include:
- Prefer native process APIs that pass executable arguments separately rather than invoking a shell.
- Treat profile fields as untrusted data and apply strict, context-appropriate validation.
- Use allowlisted character sets and bounded lengths for Git author identity fields where compatible with application requirements.
- Avoid dynamic command-string construction and ensure argument escaping is not the sole security boundary.
- Restrict the web-server account's filesystem, repository, and process privileges.
- Limit which authenticated roles can alter author identity fields or trigger synchronization operations.
- Keep sensitive credentials and writable repositories outside unnecessarily privileged application contexts.
How teams detect issues like this
Detection approaches may include:
- Static analysis rules identifying
exec(), shell invocation, and dynamically concatenated command strings. - Searches for Git command construction that incorporates request, profile, metadata, or form values.
- Code review checks for missing argument separation, allowlisting, and validation at trust boundaries.
- Runtime monitoring for unexpected child processes spawned by the web server or CMS process.
- Audit logging of author-field changes, commit operations, and process execution failures.
- Policy enforcement that blocks shell-capable APIs in application code unless narrowly reviewed and justified.
Detection approaches may include:
- Static analysis rules identifying
exec(), shell invocation, and dynamically concatenated command strings. - Searches for Git command construction that incorporates request, profile, metadata, or form values.
- Code review checks for missing argument separation, allowlisting, and validation at trust boundaries.
- Runtime monitoring for unexpected child processes spawned by the web server or CMS process.
- Audit logging of author-field changes, commit operations, and process execution failures.
- Policy enforcement that blocks shell-capable APIs in application code unless narrowly reviewed and justified.
