How severe is CVE-2021-27692?

CVE-2021-27692 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-2021-27692 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27692?

CVE-2021-27692 primarily affects Tendacn G1 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27692?

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-2021-27692 published?

CVE-2021-27692 was published on 2021-04-16 and last updated on 2026-06-17.

CVE-2021-27692

CVE-2021-27692 is a critical-severity vulnerability in Tendacn G1 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: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Tendacn G1 Firmware
Published: 2021-04-16
Last modified: 2026-06-17

Description

Command Injection in Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted "action/umountUSBPartition" request. This occurs because the "formSetUSBPartitionUmount" function executes the "doSystemCmd" function with untrusted input.

Frequently asked questions

What is CVE-2021-27692?: Command Injection in Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted "action/umountUSBPartition" request. This occurs because the "formSetUSBPartitionUmount" function executes the "doSystemCmd" function with untrusted input.
How severe is CVE-2021-27692?: CVE-2021-27692 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-2021-27692 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27692?: CVE-2021-27692 primarily affects Tendacn G1 Firmware. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27692?: 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-2021-27692 published?: CVE-2021-27692 was published on 2021-04-16 and last updated on 2026-06-17.

References

https://hackmd.io/%40aZYpdinUS2SD-yhAeHwOkw/ry-t4QfMu

Affected products (4)

cpe:2.3:o:tendacn:g1_firmware:15.11.0.16\(9024\)_cn:*:*:*:*:*:*:*
cpe:2.3:o:tendacn:g1_firmware:15.11.0.17\(9502\)_cn:*:*:*:*:*:*:*
cpe:2.3:o:tendacn:g3_firmware:15.11.0.16\(9024\)_cn:*:*:*:*:*:*:*
cpe:2.3:o:tendacn:g3_firmware:15.11.0.17\(9502\)_cn:*:*:*:*:*:*:*

More vulnerabilities in Tendacn G1 Firmware

CVE-2022-24171 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…
CVE-2022-24170 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…
CVE-2022-24168 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…
CVE-2022-24167 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…
CVE-2022-24165 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…
CVE-2021-45990 — Critical (CVSS 9.8): Tenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a command injection vulnerability in the…

All CVEs affecting Tendacn G1 Firmware →

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