Tenda FH303/A300 V5.07.68_EN Cookie Session Weakness DNS Change

published 2026-04-29 6 mo ago modified 2026-10-01 38 d ago also EUVD-2018-21839

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits: 0; none known

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.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: total
Assessed: 6 mo ago (2026-04-30)

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

exploit-db.com https://www.exploit-db.com/exploits/44381 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	9.3	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
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	4.0	9.3	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/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

Affected products

Tenda FH303/A300

Classification

Weakness

CWE-290 Authentication Bypass by Spoofing

References

exploit-db.com /exploits/44381
exploit, third-party-advisory, vdb-entry
vulncheck.com /advisories/tenda-fh303-a300-68-en-cookie-session-weakness-dns-change
third-party-advisory

Sources

CVE List CVE-2018-25318
NVD CVE-2018-25318

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary