CASCACascade Atlas

Evidence dossier

CVE-2020-8515

CVE-2020-8515

84.5–100.0Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI. This issue has been fixed in Vigor3900/2960/300B v1.5.1.

State
PUBLISHED
Published
Feb 1, 2020
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS99.99%

2026-07-18 · v2026.06.15 · percentile 100.0%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

mitreoriginal assertion
container

DrayTek Vigor2960 1.3.1_Beta, Vigor3900 1.4.4_Beta, and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI. This issue has been fixed in Vigor3900/2960/300B v1.5.1.

CISA KEVoriginal assertion
observed_exploitation

Multiple DrayTek Vigor Routers Web Management Page Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.999930000000; percentile 0.999860000000

Applicability

Cited product scope

Trace impact →
n/an/a
[{"status": "affected", "version": "n/a"}]unknown
Unknown vendorUnknown product
cpe:2.3:h:draytek:vigor2960:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:draytek:vigor300b:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:h:draytek:vigor3900:-:*:*:*:*:*:*:*constrained
Unknown vendorUnknown product
cpe:2.3:o:draytek:vigor2960_firmware:1.3.1:beta:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:draytek:vigor300b_firmware:1.3.3:beta:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:draytek:vigor300b_firmware:1.4.2.1:beta:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:draytek:vigor300b_firmware:1.4.4:beta:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:draytek:vigor3900_firmware:1.4.4:beta:*:*:*:*:*:*supported

Assessments

CVSS by origin

9.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8
134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.