Chamilo: Improper Handling of Case Sensitivity
CVE-2023-3545 is a critical-severity improper handling of case sensitivity vulnerability in Chamilo, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Chamilo versions: 1.11.20 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.44% chance of exploitation within 30 days, higher than 85% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Chamilo you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on support.chamilo.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
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
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA (starlabs.sg) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Improper sanitisation in `main/inc/lib/fileUpload.lib.php` in Chamilo LMS <= v1.11.20 on Windows and Apache installations allows unauthenticated attackers to bypass file upload security protections and obtain remote code execution via uploading of `.htaccess` file. This vulnerability may be exploited by privileged attackers or chained with unauthenticated arbitrary file write vulnerabilities, such as CVE-2023-3533, to achieve remote code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Case Sensitivity
The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.
How developers prevent this class of flaw
- Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
More Improper Handling of Case Sensitivity vulnerabilities (CWE-178)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Technical write-ups (may include proof of concept)
- starlabs.sg/advisories/23/23-3545/Exploit, Third Party Advisory
Other vulnerabilities in Chamilo
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Improper Handling of Case Sensitivity vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
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