CVE-2026-73673

HIGH
MEDIUM Priority: 0.05 BB Relevance: 63/100
Published: 2026-08-14 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Adjacent Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Adjacent
AC: Low
PR: None
UI: None
S: X
AT: None
VC: High
VI: High
VA: High

Description

Netis NC63 router firmware V3.0.0.3327 contains an unauthenticated firmware update vulnerability that allows unauthenticated attackers to submit unsigned firmware images by exploiting a missing authentication enforcement flaw in the Boa web server and netis.cgi CGI dispatcher. Attackers can send a multipart POST request to /cgi-bin/upload_fw.cgi without a valid session cookie, bypassing authentication because Boa grants access to any path containing '.cgi' regardless of cookie validation, and netis.cgi reads but does not enforce the authentication state before invoking the firmware update handler, which accepts images validated only by a forgeable additive checksum and static product strings rather than a cryptographic signature, potentially enabling persistent router compromise.

Weakness Classification (1)

Bug Bounty Relevance

63 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.7 / 10.0 v4.0
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.54%
Raw Score 0.005430
Percentile 45.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00543
2026-10-28
0.00543

Intelligence Sources

nvd ref →