How severe is CVE-2021-35327?

CVE-2021-35327 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-2021-35327 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-35327?

CVE-2021-35327 affects Totolink A720r Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-35327?

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-2021-35327 published?

CVE-2021-35327 was published on 2021-08-05 and last updated on 2026-06-17.

CVE-2021-35327

CVE-2021-35327 is a critical-severity vulnerability in Totolink A720r 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-862.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Totolink A720r Firmware
Published: 2021-08-05
Last modified: 2026-06-17

Description

A vulnerability in TOTOLINK A720R A720R_Firmware v4.1.5cu.470_B20200911 allows attackers to start the Telnet service, then login with the default credentials via a crafted POST request.

Frequently asked questions

What is CVE-2021-35327?: A vulnerability in TOTOLINK A720R A720R_Firmware v4.1.5cu.470_B20200911 allows attackers to start the Telnet service, then login with the default credentials via a crafted POST request.
How severe is CVE-2021-35327?: CVE-2021-35327 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-2021-35327 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35327?: CVE-2021-35327 affects Totolink A720r Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-35327?: 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-2021-35327 published?: CVE-2021-35327 was published on 2021-08-05 and last updated on 2026-06-17.

References

https://github.com/hurricane618/my_cves/blob/master/router/totolink/A720R_default_telnet_info.md

Affected products (1)

cpe:2.3:o:totolink:a720r_firmware:4.1.5cu.470_b20200911:*:*:*:*:*:*:*

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