What is the CVSS score of EUVD-2018-21839?

EUVD-2018-21839 has a CVSS 4.0 base score of 9.3 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for EUVD-2018-21839?

Yes, a public proof-of-concept exploit is available for EUVD-2018-21839. Prioritise patching immediately. EPSS: 0.0%.

Tenda EUVD-2018-21839

| CVE-2018-25318 CRITICAL

Authentication Bypass by Spoofing (CWE-290)

2026-04-29 VulnCheck

Authentication Bypass Tenda

9.3

CVSS 4.0 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-290 OWASP Top 10:2025 A07:2025 - Authentication Failures ASVS 5.0 V6 - Authentication Anti-spoofing controls MITRE ATT&CK 1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS score of 9.3 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. EPSS exploitation probability: 0.04%.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the critical-severity affected system.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.

No patch listed yet 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

Tenda FH303/A300 firmware V5.07.68_EN contains a session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient cookie validation. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affected VersionsENISA

FH303/A300 5.07.68

Affected Packages

euvd fh303_a300 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-290. Tenda FH303/A300 firmware V5.07.68_EN contains a session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient cookie validation. Attackers can send GET requests to the /goform/AdvSetDns endpoint with a crafted admin cookie to change DNS servers and redirect user traffic to malicious sites. Affected products include: Tenda Fh303/A300.

Know when Tenda gets its next vulnerability

Watch products and get an email when something new is published
Check this CVE against your own stack and servers
Exploit and PoC references, threat intelligence from 22 sources

Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 9.3 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

High

Vulnerable system: Integrity

High

Vulnerable system: Availability

High

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

PoC Detected

May 04, 2026 - 18:40 vuln.today

Public exploit code

CVSS changed

Apr 29, 2026 - 20:22 NVD

9.8 (CRITICAL) 9.3 (CRITICAL)

CVE Published

Apr 29, 2026 - 19:24 nvd

CRITICAL 9.3

DescriptionCVE.org

Tenda FH303/A300 firmware V5.07.68_EN contains a session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient cookie validation. Attackers can send GET requests to the /goform/AdvSetDns endpoint with a crafted admin cookie to change DNS servers and redirect user traffic to malicious sites.

Threat Intelligence Overview

EPSS Score

0.0%

Top 87% exploitable

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment

Exploit-DB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

CRITICAL severity + public POC available

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation

Poc

System Exposure· derived

Open

Automatable

Yes

Human Impact· derived

Medium

Technical Impact

Total

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +46

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Authentication Bypass CRITICAL

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

More in Tenda

View all

CVE-2022-30023 HIGH Act Now POC

8.8 Jun 16

Tenda ONT GPON AC1200 Dual band WiFi HG9 v1.0.1 is vulnerable to Command Injection via the Ping function. Rated high sev

CVE-2015-5995 CRITICAL Emergency POC

9.8 Dec 31

Mediabridge Medialink MWN-WAPR300N devices with firmware 5.07.50 and Tenda N3 Wireless N150 devices allow remote attacke

CVE-2014-5246 CRITICAL Emergency POC

10.0 Aug 22

The Shenzhen Tenda Technology Tenda A5s router with firmware 3.02.05_CN allows remote attackers to bypass authentication

CVE-2025-45042 CRITICAL Emergency POC

9.8 May 05

Tenda AC9 v15.03.05.14 was discovered to contain a command injection vulnerability via the Telnet function. Rated critic

CVE-2025-29384 CRITICAL Emergency POC

9.8 Mar 14

In Tenda AC9 v1.0 V15.03.05.14_multi, the wanMTU parameter of /goform/AdvSetMacMtuWan has a stack overflow vulnerability

CVE-2025-44877 CRITICAL Emergency POC

9.8 May 02

Tenda AC9 V15.03.06.42_multi was found to contain a command injection vulnerability in the formSetSambaConf function via

CVE-2025-44872 CRITICAL Emergency POC

9.8 May 02

Tenda AC9 V15.03.06.42_multi was found to contain a command injection vulnerability in the formsetUsbUnload function via

CVE-2022-32386 CRITICAL Emergency POC

9.8 Jul 06

Tenda AC23 v16.03.07.44 was discovered to contain a buffer overflow via fromAdvSetMacMtuWan. Rated critical severity (CV

CVE-2025-25632 CRITICAL Emergency POC

9.8 Mar 05

Tenda AC15 v15.03.05.19 is vulnerable to Command Injection via the handler function in /goform/telnet. Rated critical se

CVE-2023-51972 CRITICAL Act Now POC

9.8 Jan 10

Tenda AX1803 v1.0.0.1 was discovered to contain a command injection vulnerability via the function fromAdvSetLanIp. Rate

CVE-2023-51812 CRITICAL Act Now POC

9.8 Jan 04

Tenda AX3 v16.03.12.11 was discovered to contain a remote code execution (RCE) vulnerability via the list parameter at /

CVE-2023-23080 CRITICAL Act Now POC

9.8 Feb 27

Certain Tenda products are vulnerable to command injection. Rated critical severity (CVSS 9.8), this vulnerability is re

Same weakness CWE-290 – Authentication Bypass by Spoofing

View all

CVE-2026-104935 HIGH POC

8.6

CVE-2026-102764 CRITICAL POC

9.3

CVE-2024-54085 CRITICAL

9.8

CVE-2023-50224 MEDIUM

6.5

CVE-2024-4358 CRITICAL POC

9.8

CVE-2018-5353 CRITICAL POC

9.8

CVE-2023-51350 CRITICAL POC

9.8

CVE-2022-3180 CRITICAL

9.8

Same technique Authentication Bypass

View all

CVE-2015-3306 CRITICAL POC

10.0

CVE-2023-22515 CRITICAL POC

9.8

CVE-2012-4681 CRITICAL POC

9.8

CVE-2013-2465 CRITICAL POC

9.8

CVE-2011-3544 CRITICAL POC

9.8

CVE-2022-40684 CRITICAL POC

9.8

CVE-2025-61882 CRITICAL POC

9.8

CVE-2024-0012 CRITICAL POC

9.3

References

Advisories & patches

REF https://www.vulncheck.com/advisories/tenda-fh303-a300-68-en-cookie-session-weakness-dns-change

Search Externally

GitHub PoC

Exploit-DB PacketStorm Snyk Rapid7 Nuclei Templates Trickest PoC

Back