How severe is CVE-2021-39278?

CVE-2021-39278 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-39278 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39278?

CVE-2021-39278 primarily affects Moxa Wac-2004 Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-39278?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-39278 published?

CVE-2021-39278 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2021-39278

CVE-2021-39278 is a medium-severity vulnerability in Moxa Wac-2004 Firmware with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Moxa Wac-2004 Firmware
Published: 2021-09-07
Last modified: 2026-06-17

Description

Certain MOXA devices allow reflected XSS via the Config Import menu. This affects WAC-2004 1.7, WAC-1001 2.1, WAC-1001-T 2.1, OnCell G3470A-LTE-EU 1.7, OnCell G3470A-LTE-EU-T 1.7, TAP-323-EU-CT-T 1.3, TAP-323-US-CT-T 1.3, TAP-323-JP-CT-T 1.3, WDR-3124A-EU 2.3, WDR-3124A-EU-T 2.3, WDR-3124A-US 2.3, and WDR-3124A-US-T 2.3.

Frequently asked questions

What is CVE-2021-39278?: Certain MOXA devices allow reflected XSS via the Config Import menu. This affects WAC-2004 1.7, WAC-1001 2.1, WAC-1001-T 2.1, OnCell G3470A-LTE-EU 1.7, OnCell G3470A-LTE-EU-T 1.7, TAP-323-EU-CT-T 1.3, TAP-323-US-CT-T 1.3, TAP-323-JP-CT-T 1.3, WDR-3124A-EU 2.3, WDR-3124A-EU-T 2.3, WDR-3124A-US 2.3, and WDR-3124A-US-T 2.3.
How severe is CVE-2021-39278?: CVE-2021-39278 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-39278 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39278?: CVE-2021-39278 primarily affects Moxa Wac-2004 Firmware. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-39278?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39278 published?: CVE-2021-39278 was published on 2021-09-07 and last updated on 2026-06-17.

References

http://packetstormsecurity.com/files/164014

Affected products (12)

cpe:2.3:o:moxa:wac-2004_firmware:1.7:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wac-1001_firmware:2.1:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wac-1001-t_firmware:2.1:*:*:*:*:*:*:*
cpe:2.3:o:moxa:oncell_g3470a-lte-eu_firmware:1.7:*:*:*:*:*:*:*
cpe:2.3:o:moxa:oncell_g3470a-lte-eu-t_firmware:1.7:*:*:*:*:*:*:*
cpe:2.3:o:moxa:tap-323-eu-ct-t_firmware:1.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:tap-323-us-ct-t_firmware:1.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:tap-323-jp-ct-t_firmware:1.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wdr-3124a-eu_firmware:2.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wdr-3124a-eu-t_firmware:2.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wdr-3124a-us_firmware:2.3:*:*:*:*:*:*:*
cpe:2.3:o:moxa:wdr-3124a-us-t_firmware:2.3:*:*:*:*:*:*:*

More vulnerabilities in Moxa Wac-2004 Firmware

CVE-2016-8363 — Critical (CVSS 10.0): An issue was discovered in Moxa OnCell OnCellG3470A-LTE, AWK-1131A/3131A/4131A Series, AWK-3191 Series, AWK-5232/6232…
CVE-2021-39279 — High (CVSS 8.8): Certain MOXA devices allow Authenticated Command Injection via /forms/web_importTFTP. This affects WAC-2004 1.7,…
CVE-2016-8362 — Medium (CVSS 6.5): An issue was discovered in Moxa OnCell OnCellG3470A-LTE, AWK-1131A/3131A/4131A Series, AWK-3191 Series, AWK-5232/6232…

All CVEs affecting Moxa Wac-2004 Firmware →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →