Security readout for executives and security teams
Plain-English summary
This flaw affects older DrayTek Vigor2960, Vigor3900, and Vigor300B devices. A remote attacker could exploit a stack-based buffer overflow to run arbitrary code on the device. Because these are network edge devices, compromise could affect connectivity and network trust boundaries.
Executive priority
Prioritize remediation for any affected DrayTek device exposed to the internet or third parties. This is a remote code execution class issue on network infrastructure, but the source bundle does not prove active exploitation.
Technical view
CVE-2020-14993 is a stack-based buffer overflow in DrayTek firmware before 1.5.1.1. The CVE description identifies the vulnerable path as the formuserphonenumber parameter in an authusersms action to mainfunction.cgi. The public bundle includes a proof-of-concept reference, but no CVSS vector or CWE metadata.
Likely exposure
Organizations are exposed if they still operate DrayTek Vigor2960, Vigor3900, or Vigor300B devices running firmware earlier than 1.5.1.1, especially where the affected web management functionality is reachable by untrusted networks.
Exploitation context
The bundle includes a public GitHub proof-of-concept reference. It does not include KEV status, CVSS scoring, confirmed active exploitation, authentication requirements, or internet-wide exploitation evidence. Treat public exposure seriously, but do not assume active exploitation from these sources alone.
Researcher notes
The CVE references CVE-2020-14993, while one DrayTek advisory URL names CVE-2020-14473. The bundle does not resolve that mismatch. Validate against DrayTek’s advisory and the exact firmware branch before making final exposure calls.
Mitigation direction
- Inventory DrayTek Vigor2960, Vigor3900, and Vigor300B devices.
- Upgrade affected devices to firmware 1.5.1.1 or later per DrayTek guidance.
- Review DrayTek’s security advisory for product-specific instructions.
- Limit management interface exposure to trusted administrative networks.
- Monitor affected devices for unexpected configuration or authentication changes.
Validation and detection
- Confirm device model and firmware version from management records.
- Verify no affected device remains below firmware 1.5.1.1.
- Check whether management interfaces are reachable from untrusted networks.
- Review logs for suspicious requests to mainfunction.cgi.
- Document upgrade status and any compensating access controls.
Public sources used
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.
Execution 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 lookupCVE-2020-14993 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/dexterone/Vigor-pocCVE reference · x_refsource_MISC
- https://www.draytek.com/about/security-advisoryCVE reference · x_refsource_MISC
- https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-stack-based-buffer-overflow-vulnerability-%28cve-2020-14473%29CVE reference · x_refsource_CONFIRM
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.