Description
An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the value of `userInfo`. When `userInfo` is passed into the `addAuthUser` function and processed by `sscanf` without size validation, it could lead to buffer overflow.
Published: 2026-03-02
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

An input validation flaw in Tenda W20E’s addAuthUser function allows a buffer overflow when the supplied userInfo string is processed by sscanf without length checks. The overflow can corrupt adjacent memory, giving an attacker the potential to execute arbitrary code, elevate privileges, or crash the device. The weakness is identified as CWE‑120.

Affected Systems

Affected systems are the Tenda W20E router with firmware V4.0br_V15.11.0.6 and firmware 15.11.0.6; no other vendors are listed as impacted.

Risk and Exploitability

The vulnerability scores a CVSS of 9.8, indicating critical severity. The EPSS probability is less than 1 % and the flaw is not yet listed in the CISA KEV catalog. The likely attack vector is sending a crafted userInfo parameter to the router’s HTTP management interface, which causes the unchecked sscanf call to overflow the buffer. Security teams should treat this as a high‑risk threat and prioritize remediation accordingly.

Generated by OpenCVE AI on April 18, 2026 at 10:11 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply an updated firmware that fixes the unchecked sscanf usage.
  • If a patch is unavailable, disable or block the vulnerable management endpoint to prevent malicious input.
  • Segment the device or place it behind a firewall to reduce exposure and monitor traffic for suspicious activity.

Generated by OpenCVE AI on April 18, 2026 at 10:11 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Thu, 05 Mar 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 03 Mar 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Tenda
Tenda w20e
Tenda w20e Firmware
Weaknesses CWE-120
CPEs cpe:2.3:h:tenda:w20e:4.0:*:*:*:*:*:*:*
cpe:2.3:o:tenda:w20e_firmware:15.11.0.6:*:*:*:*:*:*:*
Vendors & Products Tenda
Tenda w20e
Tenda w20e Firmware
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Mon, 02 Mar 2026 15:15:00 +0000

Type Values Removed Values Added
Description An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the value of `userInfo`. When `userInfo` is passed into the `addAuthUser` function and processed by `sscanf` without size validation, it could lead to buffer overflow.
References

Subscriptions

Tenda W20e W20e Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-03-05T15:56:42.518Z

Reserved: 2026-01-21T00:00:00.000Z

Link: CVE-2026-24111

cve-icon Vulnrichment

Updated: 2026-03-05T15:56:19.305Z

cve-icon NVD

Status : Modified

Published: 2026-03-02T15:16:33.497

Modified: 2026-03-05T16:16:15.497

Link: CVE-2026-24111

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-18T10:15:25Z

Weaknesses