CVE-2021-20862

Improper access control vulnerability in ELECOM routers (WRC-1167GST2 firmware v1.25 and prior, WRC-1167GST2A firmware v1.25 and prior, WRC-1167GST2H firmware v1.25 and prior, WRC-2533GS2-B firmware v1.52 and prior, WRC-2533GS2-W firmware v1.52 and prior, WRC-1750GS firmware v1.03 and prior, WRC-1750GSV firmware v2.11 and prior, WRC-1900GST firmware v1.03 and prior, WRC-2533GST firmware v1.03 and prior, WRC-2533GSTA firmware v1.03 and prior, WRC-2533GST2 firmware v1.25 and prior, WRC-2533GST2SP firmware v1.25 and prior, WRC-2533GST2-G firmware v1.25 and prior, and EDWRC-2533GST2 firmware v1.25 and prior) allows a network-adjacent unauthenticated attacker to bypass access restriction, and to obtain anti-CSRF tokens and change the product's settings via unspecified vectors.

Published: 2021-11-30 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20862 is rated Low Risk (27.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.37%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-20862

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 2026-06-15 0.05% 0.37% +0.32%
2 2023-05-13 0.05% 0.05% +0.01%
3 2023-03-07 — 0.05% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20862

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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: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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]
3.3 2.0 LOW
AV:A/AC:L/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:A)
Requires access to an adjacent network segment.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
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.
 6.5 2.9 [email protected]

Weakness enumeration for CVE-2021-20862

Affected software / configurations for CVE-2021-20862

Vendor Product Version Raw CPE
elecom wrc-1167gst2_firmware <= 1.25 cpe:2.3:o:elecom:wrc-1167gst2_firmware:*:*:*:*:*:*:*:*
elecom wrc-1167gst2a_firmware <= 1.25 cpe:2.3:o:elecom:wrc-1167gst2a_firmware:*:*:*:*:*:*:*:*
elecom wrc-1167gst2h_firmware <= 1.25 cpe:2.3:o:elecom:wrc-1167gst2h_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gs2-b_firmware <= 1.52 cpe:2.3:o:elecom:wrc-2533gs2-b_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gs2-w_firmware <= 1.52 cpe:2.3:o:elecom:wrc-2533gs2-w_firmware:*:*:*:*:*:*:*:*
elecom wrc-1750gs_firmware <= 1.03 cpe:2.3:o:elecom:wrc-1750gs_firmware:*:*:*:*:*:*:*:*
elecom wrc-1750gsv_firmware <= 2.11 cpe:2.3:o:elecom:wrc-1750gsv_firmware:*:*:*:*:*:*:*:*
elecom wrc-1900gst_firmware <= 1.03 cpe:2.3:o:elecom:wrc-1900gst_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gst_firmware <= 1.03 cpe:2.3:o:elecom:wrc-2533gst_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gst2_firmware <= 1.25 cpe:2.3:o:elecom:wrc-2533gst2_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gsta_firmware <= 1.03 cpe:2.3:o:elecom:wrc-2533gsta_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gst2sp_firmware <= 1.25 cpe:2.3:o:elecom:wrc-2533gst2sp_firmware:*:*:*:*:*:*:*:*
elecom wrc-2533gst2-g_firmware <= 1.25 cpe:2.3:o:elecom:wrc-2533gst2-g_firmware:*:*:*:*:*:*:*:*
elecom edwrc-2533gst2_firmware <= 1.25 cpe:2.3:o:elecom:edwrc-2533gst2_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-20862

cvelogic Threat Intelligence