GHSA-c7jj-vfmr-j9mj BIT-moodle-2021-21809 CVE-2021-21809
Moodle command execution vulnerability exists in the default legacy spellchecker plugin
Critical
Packagist
- Severity
- 9.1 / 10
- Critical · CVSS 3.1
- Exploit chance (EPSS)
- 24.17%
- Chance of exploitation in the next 30 days. Higher than 97.85% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-732 Incorrect Permission Assignment for Critical Resource
- Fix
- None yet
- No fixed version published
Description
A command execution vulnerability exists in the default legacy spellchecker plugin in a few Moodle multiple specific versions. A specially crafted series of HTTP requests can lead to command execution. An attacker must have administrator privileges to exploit this vulnerabilities.
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| moodle/moodle | 1 listed versions | No fix yet |
| moodle/moodle | 1 listed versions | No fix yet |
| moodle/moodle | 1 listed versions | No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 9.1
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-732: Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
How to prevent it
- Implementation: When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user) [REF-62], and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
- Architecture and Design: Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources. [REF-207]
- Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Implementation, Installation: During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
- System Configuration: For all configuration files, executables, and libraries, make sure that they are only readable and writable by the software's administrator.
- Documentation: Do not suggest insecure configuration changes in documentation, especially if those configurations can extend to resources and other programs that are outside the scope of the application.
- Installation: Do not assume that a system administrator will manually change the configuration to the settings that are recommended in the software's manual.
- Operation, System Configuration: Ensure that the software runs properly under the United States Government Configuration Baseline (USGCB) [REF-199] or an equivalent hardening configuration guide, which many organizations use to limit the attack surface and potential risk of deployed software.
- Implementation, System Configuration, Operation: When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-cg8j-5cr2-568q Moodle TeX formula editor is vulnerable to DoS through lack of execution time limits | Medium | Also affects moodle/moodle |
| GHSA-ggxq-2mg9-8966 Moodle has a Remote Code Execution risk via file restore | High | Also affects moodle/moodle |
| GHSA-8jrv-wx83-w3xj Moodle Inserts Sensitive Information Into Sent Data | Medium | Also affects moodle/moodle |
| GHSA-hcm6-q6pc-xfhm Moodle has an authorization logic flaw | Critical | Also affects moodle/moodle |
| GHSA-vwhw-vp9v-q9c9 Moodle vulnerable to Cross-site Scripting | Medium | Also affects moodle/moodle |
| GHSA-5cx4-w4fh-fr57 Moodle Affected by Improper Restriction of Excessive Authentication Attempts | High | Also affects moodle/moodle |
| GHSA-qv78-6gpp-hm68 Moodle Open Redirect vulnerability | Medium | Also affects moodle/moodle |
| GHSA-qfh6-h7j6-fvjv Moodle formula injection vulnerability | High | Also affects moodle/moodle |
MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.
Check your repos with MergeHarbor