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Fencer Intel
high 7.5

CVE-2021-47740 json

KZTech JT3500V 4G LTE CPE 2.0.1 Insufficient Session Expiration Vulnerability

published 10mo ago modified 4mo ago also EUVD-2025-206077

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

KZTech JT3500V 4G LTE CPE 2.0.1 contains a session management vulnerability that allows attackers to reuse old session credentials without proper expiration. Attackers can exploit the weak session handling to maintain unauthorized access and potentially compromise device authentication mechanisms.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
10mo ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • packetstormsecurity.com https://packetstormsecurity.com/files/161892/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/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

  • KZ Broadband Technologies, Ltd. JT3500V
  • KZ Broadband Technologies, Ltd. AM6200M
  • KZ Broadband Technologies, Ltd. AM6000N
  • KZ Broadband Technologies, Ltd. AM5000W
  • KZ Broadband Technologies, Ltd. AM4200M
  • KZ Broadband Technologies, Ltd. AM4100V
  • KZ Broadband Technologies, Ltd. AM3500MW
  • KZ Broadband Technologies, Ltd. AM3410V
  • KZ Broadband Technologies, Ltd. AM3300V
  • KZ Broadband Technologies, Ltd. AM3100E
  • KZ Broadband Technologies, Ltd. AM3100V
  • KZ Broadband Technologies, Ltd. AM3000M
  • KZ Broadband Technologies, Ltd. KZ7621U
  • KZ Broadband Technologies, Ltd. KZ3220M
  • KZ Broadband Technologies, Ltd. KZ3120R

Classification

Weakness
  • CWE-613 DEPRECATED: Insufficient Session Expiration

References

Sources

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.