Security readout for executives and security teams
Plain-English summary
CVE-2020-37113 affects GUnet OpenEclass 1.7.3. A logged-in user can evade file upload restrictions and place executable server-side code through the exercise submission feature, potentially taking control of the web server. This is high risk for any still-running legacy instance.
Executive priority
Treat as urgent for any active OpenEclass 1.7.3 system. The combination of remote code execution, public exploit information, and low attacker requirements creates material risk, even though active exploitation is not confirmed in the provided sources.
Technical view
The issue is CWE-434: unrestricted upload of a dangerous file type. In OpenEclass 1.7.3, extension filtering can be bypassed using alternate PHP extension or case variants, enabling remote code execution after authenticated upload. CVSS is 8.8, with network access, low complexity, and low privileges required.
Likely exposure
Exposure is likely limited to organizations still running GUnet OpenEclass 1.7.3, a legacy 2007 release, especially where authenticated users can submit exercise files. Public internet exposure increases urgency.
Exploitation context
A public Exploit-DB entry exists, so technical details are publicly available. The source bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation requires an authenticated account with access to the vulnerable upload workflow.
Researcher notes
Evidence points to a file upload validation flaw in OpenEclass 1.7.3 only. Do not assume other versions are affected without vendor confirmation. The provided sources do not name a specific fixed release; validate remediation through official vendor materials.
Mitigation direction
- Identify any OpenEclass 1.7.3 deployments and prioritize retirement or upgrade.
- Review vendor site and changelog for supported fixed versions or migration guidance.
- Restrict access to file submission features until remediation is complete.
- Block execution from upload directories using web server controls, if supported.
- Monitor uploaded files and web logs for suspicious server-side script activity.
Validation and detection
- Confirm installed OpenEclass version from application inventory or administration records.
- Determine whether the exercise submission upload feature is enabled.
- Verify which user roles can upload exercise submissions.
- Review upload directories for executable script files or unusual case/extension variants.
- Check whether the application is internet-accessible or limited to trusted networks.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-37113 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-48163CVE reference · exploit
- Official Vendor HomepageCVE reference · product
- ChangelogCVE reference · patch
- VulnCheck Advisory: GUnet OpenEclass 1.7.3 E-learning platform - File Upload Extension BypassCVE reference · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.