CVE-2021-39243

Exp

Cross-Site Request Forgery (CSRF) exists on Altus Nexto, Nexto Xpress, and Hadron Xtorm devices via any CGI endpoint. This affects Nexto NX3003 1.8.11.0, Nexto NX3004 1.8.11.0, Nexto NX3005 1.8.11.0, Nexto NX3010 1.8.3.0, Nexto NX3020 1.8.3.0, Nexto NX3030 1.8.3.0, Nexto NX5100 1.8.11.0, Nexto NX5101 1.8.11.0, Nexto NX5110 1.1.2.8, Nexto NX5210 1.1.2.8, Nexto Xpress XP300 1.8.11.0, Nexto Xpress XP315 1.8.11.0, Nexto Xpress XP325 1.8.11.0, Nexto Xpress XP340 1.8.11.0, and Hadron Xtorm HX3040 1.7.58.0.

Published: 2021-08-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-39243 is rated Exploit Available (54.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-39243

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-39243

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-15 0.07% 0.17% +0.10%
2 2023-03-07 0.89% 0.07% -0.82%
3 2022-04-01 — 0.89% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-39243

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-39243

Affected software / configurations for CVE-2021-39243

Vendor Product Version Raw CPE
altus nexto_nx3003_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_nx3003_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_nx3004_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_nx3004_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_nx3005_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_nx3005_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_nx3010_firmware 1.8.3.0 cpe:2.3:o:altus:nexto_nx3010_firmware:1.8.3.0:*:*:*:*:*:*:*
altus nexto_nx3020_firmware 1.8.3.0 cpe:2.3:o:altus:nexto_nx3020_firmware:1.8.3.0:*:*:*:*:*:*:*
altus nexto_nx3030_firmware 1.8.3.0 cpe:2.3:o:altus:nexto_nx3030_firmware:1.8.3.0:*:*:*:*:*:*:*
altus nexto_nx5100_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_nx5100_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_nx5101_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_nx5101_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_nx5110_firmware 1.1.2.8 cpe:2.3:o:altus:nexto_nx5110_firmware:1.1.2.8:*:*:*:*:*:*:*
altus nexto_nx5210_firmware 1.1.2.8 cpe:2.3:o:altus:nexto_nx5210_firmware:1.1.2.8:*:*:*:*:*:*:*
altus nexto_xpress_xp300_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_xpress_xp300_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_xpress_xp315_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_xpress_xp315_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_xpress_xp325_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_xpress_xp325_firmware:1.8.11.0:*:*:*:*:*:*:*
altus nexto_xpress_xp340_firmware 1.8.11.0 cpe:2.3:o:altus:nexto_xpress_xp340_firmware:1.8.11.0:*:*:*:*:*:*:*
altus hadron_xtorm_hx3040_firmware 1.7.58.0 cpe:2.3:o:altus:hadron_xtorm_hx3040_firmware:1.7.58.0:*:*:*:*:*:*:*

References for CVE-2021-39243

URL Tags
http://seclists.org/fulldisclosure/2021/Aug/21 Exploit Mailing List Third Party Advisory
https://www.altus.com.br/ Vendor Advisory
cvelogic Threat Intelligence