Security readout for executives and security teams
Plain-English summary
CVE-2020-15415 is a critical remote code execution flaw in older DrayTek Vigor3900, Vigor2960, and Vigor300B firmware. An unauthenticated network attacker could potentially run commands on the device. CISA lists it in KEV, so organizations should treat exposed or outdated appliances as urgent.
Executive priority
Treat this as urgent for any exposed affected appliance. The weakness allows unauthenticated remote code execution, affects perimeter networking equipment, and is listed by CISA as known exploited. Prioritize inventory, isolation, and firmware remediation.
Technical view
The issue is CWE-78 command injection in cgi-bin/mainfunction.cgi/cvmcfgupload before firmware 1.5.1. The CVE describes shell metacharacter handling in an uploaded filename with text/x-python-script content type. CVSS 3.1 is 9.8: network reachable, low complexity, no privileges, no user interaction, and high impact.
Likely exposure
Exposure is most likely where affected DrayTek Vigor3900, Vigor2960, or Vigor300B devices run firmware before 1.5.1, especially if management or web interfaces are reachable from untrusted networks.
Exploitation context
CISA KEV inclusion supports known exploitation. The source bundle also references a public GitHub repository for this issue, indicating public technical material exists. The provided sources do not establish current campaign details, scale, or specific attacker groups.
Researcher notes
Evidence supports critical severity, unauthenticated network reachability, affected models, pre-1.5.1 firmware exposure, CWE-78, and KEV status. The bundle does not provide detailed vendor fixed-version notes beyond the “before 1.5.1” affected statement or current exploitation telemetry.
Mitigation direction
- Identify all DrayTek Vigor3900, Vigor2960, and Vigor300B devices.
- Upgrade affected devices from versions before 1.5.1 to vendor-supported fixed firmware.
- Follow DrayTek security advisory guidance for product-specific remediation.
- Restrict appliance administration interfaces from the public internet.
- Prioritize devices that are internet-facing or business-critical.
Validation and detection
- Confirm model and firmware version for each DrayTek appliance.
- Check whether management or web interfaces are internet-accessible.
- Review relevant appliance/web logs for suspicious cvmcfgupload activity.
- Verify remediation by confirming firmware is 1.5.1 or later.
- Track CISA KEV status in vulnerability management records.
Public sources used
Michael Williams reviewed this cited source version on .
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-78: Command execution behavior lookup
Command injection weaknesses can lead defenders to review execution techniques and command interpreter 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 lookupCVE-2020-15415 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/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.
CISA KEV status
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.draytek.com/about/security-advisoryCVE reference · x_refsource_MISC
- https://github.com/CLP-team/Vigor-Commond-InjectionCVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-15415CVE reference · government-resource
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.