CVE-2021-20711
CVE-2021-20711 is a critical-severity vulnerability in Nec Aterm Wg2600hs Firmware with a CVSS 3.x base score of 9.8. 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-78.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 10.0
- EPSS exploit prediction: 1% (71st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-78
- Affected product: Nec Aterm Wg2600hs Firmware
- Published:
- Last modified:
Description
Aterm WG2600HS firmware Ver1.5.1 and earlier allows an attacker to execute arbitrary OS commands via unspecified vectors.
Frequently asked questions
- What is CVE-2021-20711?
- Aterm WG2600HS firmware Ver1.5.1 and earlier allows an attacker to execute arbitrary OS commands via unspecified vectors.
- How severe is CVE-2021-20711?
- CVE-2021-20711 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-20711 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-20711?
- CVE-2021-20711 affects Nec Aterm Wg2600hs Firmware. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-20711?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2021-20711 published?
- CVE-2021-20711 was published on 2021-04-26 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:o:nec:aterm_wg2600hs_firmware:*:*:*:*:*:*:*:*
More vulnerabilities in Nec Aterm Wg2600hs Firmware
- CVE-2026-4622 — Critical (CVSS 9.8): OS Command Injection vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to execute arbitrary OS…
- CVE-2020-5524 — High (CVSS 8.8): Aterm series (Aterm WF1200C firmware Ver1.2.1 and earlier, Aterm WG1200CR firmware Ver1.2.1 and earlier, Aterm WG2600HS…
- CVE-2020-5534 — High (CVSS 8.0): Aterm WG2600HS firmware Ver1.3.2 and earlier allows an authenticated attacker on the same network segment to execute…
- CVE-2020-5525 — High (CVSS 8.0): Aterm series (Aterm WF1200C firmware Ver1.2.1 and earlier, Aterm WG1200CR firmware Ver1.2.1 and earlier, Aterm WG2600HS…
- CVE-2021-20709 — High (CVSS 7.2): Improper validation of integrity check value vulnerability in NEC Aterm WF1200CR firmware Ver1.3.2 and earlier, Aterm…
- CVE-2021-20708 — High (CVSS 7.2): NEC Aterm devices (Aterm WF1200CR firmware Ver1.3.2 and earlier, Aterm WG1200CR firmware Ver1.3.3 and earlier, and…
All CVEs affecting Nec Aterm Wg2600hs Firmware →
Other CWE-78 (OS Command Injection) vulnerabilities
- CVE-2026-100382 — Critical (CVSS 10.0): Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in Wikimedia…
- CVE-2026-77521 — Critical (CVSS 10.0): MaxKB is an open-source AI assistant for enterprise. Prior to version 2.10.5-lts, assistants with a tool, MCP tool,…
- CVE-2026-82004 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
- CVE-2026-76197 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
- CVE-2026-76195 — Critical (CVSS 10.0): Adobe Campaign Classic (ACC) is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS…
- CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…