The vulnerability was found in Moodle, occurs due to input validation error when importing…
CVE-2022-35650 is a high-severity improper input validation vulnerability in Moodle, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Moodle versions: Fixed in moodle 4.0.2, moodle 3.11.8, moodle 3.9.15. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 53.7% chance of exploitation within 30 days, which is in the top 0.99% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Check which version of Moodle you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on git.moodle.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Moodle | Moodle | Fixed in moodle 4.0.2, moodle 3.11.8, moodle 3.9.15 | Not stated |
| Fedora Project | Fedora | 35; 36 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
Official description
The vulnerability was found in Moodle, occurs due to input validation error when importing lesson questions. This insufficient path checks results in arbitrary file read risk. This vulnerability allows a remote attacker to perform directory traversal attacks. The capability to access this feature is only available to teachers, managers and admins by default.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- bugzilla.redhat.com/show_bug.cgi?id=2106274Issue Tracking, Third Party Advisory
Other references
Other vulnerabilities in Moodle
- 8.8 High severity
- 7.2 High severity
- 7.2 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.8 High severity
Recent Improper Input Validation vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 8.2 High severity
- 7.5 High severity
- 8.8 High severity
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