CVE-2021-35395Known exploitationNetwork attack vector

Remote code execution via unsafe HTTP handlers

Published Aug 16, 2021 · Updated Oct 21, 2025

Stack overflow and command injection in Realtek Jungle SDK through 3.4.14B allow remote attackers arbitrary code execution via HTTP management requests. The formRebootCheck, formWsc, formWlanMultipleAP, formWlSiteSurvey, formStaticDHCP and formSysCmd handlers copy submit-url or other parameters unsafely, enabling memory corruption and shell command execution. Reachability and authentication depend on how each router vendor integrated the SDK web server; exposed management interfaces permit remote exploitation.

CVSS severity9.8
Critical
EPSS probability97.96%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack overflow and command injection in Realtek Jungle SDK through 3.4.14B allow remote attackers arbitrary code execution via HTTP management requests. The formRebootCheck, formWsc, formWlanMultipleAP, formWlSiteSurvey, formStaticDHCP and formSysCmd handlers copy submit-url or other parameters unsafely, enabling memory corruption and shell command execution. Reachability and authentication depend on how each router vendor integrated the SDK web server; exposed management interfaces permit remote exploitation.

The record

CVE
CVE-2021-35395
Published
Aug 16, 2021
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-77, CWE-787, T1059, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsShadowserver observations through Sep 16, 2026. Gaps indicate unavailable data.
Sep 10, 2026Sep 16, 2026
View daily counts
Reporting dayUnique IPs
Sep 10, 20265
Sep 11, 20261
Sep 12, 20261
Sep 13, 20261
Sep 14, 20261
Sep 15, 2026Unavailable
Sep 16, 20261
Latest reporting daySep 16, 2026
Latest daily unique IPs1
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command
CWE-787Out-of-bounds Write
T1059Command and Scripting Interpreter
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo