CVE-2021-33903

In LCOS 10.40 to 10.42.0473-RU3 with SNMPv3 enabled on LANCOM devices, changing the password of the root user via the CLI does not change the password of the root user for SNMPv3 access. (However, changing the password of the root user via LANconfig does change the password of the root user for SNMPv3 access.)

Published: 2021-10-07 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-33903 is rated Moderate Risk (54.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.38%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2021-33903

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 2025-03-30 1.03% 0.38% -0.65%
2 2025-03-29 0.38% 1.03% +0.65%
3 2025-03-17 — 0.38% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-33903

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H 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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
8.5 2.0 HIGH
AV:N/AC:M/Au:S/C:C/I:C/A:C 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:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 6.8 10.0 [email protected]

Weakness enumeration for CVE-2021-33903

Affected software / configurations for CVE-2021-33903

Vendor Product Version Raw CPE
lancom-systems lcos >= 10.40, < 10.42.0473 cpe:2.3:o:lancom-systems:lcos:*:*:*:*:*:*:*:*
lancom-systems lcos 10.42.0473 cpe:2.3:o:lancom-systems:lcos:10.42.0473:-:*:*:*:*:*:*
lancom-systems lcos 10.42.0473 cpe:2.3:o:lancom-systems:lcos:10.42.0473:release_update1:*:*:*:*:*:*
lancom-systems lcos 10.42.0473 cpe:2.3:o:lancom-systems:lcos:10.42.0473:release_update2:*:*:*:*:*:*
lancom-systems lcos 10.42.0473 cpe:2.3:o:lancom-systems:lcos:10.42.0473:release_update3:*:*:*:*:*:*

References for CVE-2021-33903

cvelogic Threat Intelligence