CVE-2020-1866

There is an out-of-bounds read vulnerability in several products. The software reads data past the end of the intended buffer when parsing certain crafted DHCP messages. Successful exploit could cause certain service abnormal. Affected product versions include:NIP6800 versions V500R001C30,V500R001C60SPC500,V500R005C00;S12700 versions V200R008C00;S2700 versions V200R008C00;S5700 versions V200R008C00;S6700 versions V200R008C00;S7700 versions V200R008C00;S9700 versions V200R008C00;Secospace USG6600 versions V500R001C30SPC200,V500R001C30SPC600,V500R001C60SPC500,V500R005C00;USG9500 versions V500R001C30SPC300,V500R001C30SPC600,V500R001C60SPC500,V500R005C00.

Published: 2021-01-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-1866 is rated Low Risk (35.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.35%). 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-2020-1866

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 0.04% 0.35% +0.31%
2 2025-03-30 0.06% 0.04% -0.01%
3 2025-03-29 — 0.06% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-1866

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
3.3 2.0 LOW
AV:A/AC:L/Au:N/C:N/I:N/A:P 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:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 6.5 2.9 [email protected]

Weakness enumeration for CVE-2020-1866

Affected software / configurations for CVE-2020-1866

Vendor Product Version Raw CPE
huawei nip6800_firmware v500r001c30 cpe:2.3:o:huawei:nip6800_firmware:v500r001c30:*:*:*:*:*:*:*
huawei nip6800_firmware v500r001c60spc500 cpe:2.3:o:huawei:nip6800_firmware:v500r001c60spc500:*:*:*:*:*:*:*
huawei nip6800_firmware v500r005c00 cpe:2.3:o:huawei:nip6800_firmware:v500r005c00:*:*:*:*:*:*:*
huawei s12700_firmware v200r008c00 cpe:2.3:o:huawei:s12700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei s2700_firmware v200r008c00 cpe:2.3:o:huawei:s2700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei s5700_firmware v200r008c00 cpe:2.3:o:huawei:s5700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei s6700_firmware v200r008c00 cpe:2.3:o:huawei:s6700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei s7700_firmware v200r008c00 cpe:2.3:o:huawei:s7700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei s9700_firmware v200r008c00 cpe:2.3:o:huawei:s9700_firmware:v200r008c00:*:*:*:*:*:*:*
huawei secospace_usg6600_firmware v500r001c30spc200 cpe:2.3:o:huawei:secospace_usg6600_firmware:v500r001c30spc200:*:*:*:*:*:*:*
huawei secospace_usg6600_firmware v500r001c30spc600 cpe:2.3:o:huawei:secospace_usg6600_firmware:v500r001c30spc600:*:*:*:*:*:*:*
huawei secospace_usg6600_firmware v500r001c60spc500 cpe:2.3:o:huawei:secospace_usg6600_firmware:v500r001c60spc500:*:*:*:*:*:*:*
huawei secospace_usg6600_firmware v500r005c00 cpe:2.3:o:huawei:secospace_usg6600_firmware:v500r005c00:*:*:*:*:*:*:*
huawei usg9500_firmware v500r001c30spc300 cpe:2.3:o:huawei:usg9500_firmware:v500r001c30spc300:*:*:*:*:*:*:*
huawei usg9500_firmware v500r001c30spc600 cpe:2.3:o:huawei:usg9500_firmware:v500r001c30spc600:*:*:*:*:*:*:*
huawei usg9500_firmware v500r001c60spc500 cpe:2.3:o:huawei:usg9500_firmware:v500r001c60spc500:*:*:*:*:*:*:*
huawei usg9500_firmware v500r005c00 cpe:2.3:o:huawei:usg9500_firmware:v500r005c00:*:*:*:*:*:*:*

References for CVE-2020-1866

cvelogic Threat Intelligence