vulnerability / NVI-00002504 / Revision 1
Grav: Authenticated ReDoS via regex_replace in Twig Sandbox
OSV carries this publisher advisory for getgrav/grav. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
getgrav/grav
source listedECOSYSTEM: introduced 0; fixed 2.0.4
### Summary The `regex_replace` filter and function are allowlisted in Grav's Twig content sandbox. When Twig processing in page content is enabled `security.twig_content.process_enabled: true`, authenticated page editors can supply a catastrophically backtracking PCRE pattern, causing unbounded CPU consumption and denying service to the entire web server process. --- ### Details The Twig sandbox allowlists, defined in `system/config/security.yaml`, explicitly include `regex_replace` in both the filter and function permission lists: **Source: `system/config/security.yaml`** ```yaml twig_sandbox: allowed_filters: # ... - regex_replace # user-controlled pattern allowed in sandbox allowed_functions: # ... - regex_replace # same ``` The underlying implementation passes the caller-controlled `$pattern` directly into PHP's `preg_replace()` without any pattern complexity validation: **Source: `system/src/Grav/Common/Twig/Extension/GravExtension.php:1317-1319`** ```php public function regexReplace($subject, $pattern, $replace, $limit = -1) { return preg_replace($pattern, $replace, $subject, $limit); } ``` When `twig_content.process_enabled` is `tru
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 2.0.4 for getgrav/grav. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-37f3-6p89-6qr9 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.