How severe is CVE-2020-35391?

CVE-2020-35391 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-35391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 35% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-35391?

CVE-2020-35391 affects Tenda F3 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-35391?

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-2020-35391 published?

CVE-2020-35391 was published on 2021-01-01 and last updated on 2026-06-17.

CVE-2020-35391

CVE-2020-35391 is a critical-severity vulnerability in Tenda F3 Firmware with a CVSS 3.x base score of 9.6. Its EPSS exploit-prediction score of 35% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-425.

Key facts

Severity: Critical (CVSS 3.x base score 9.6)
CVSS v2: 3.3
EPSS exploit prediction: 35% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-425
Affected product: Tenda F3 Firmware
Published: 2021-01-01
Last modified: 2026-06-17

Description

Tenda N300 F3 12.01.01.48 devices allow remote attackers to obtain sensitive information (possibly including an http_passwd line) via a direct request for cgi-bin/DownloadCfg/RouterCfm.cfg, a related issue to CVE-2017-14942. NOTE: the vulnerability report may suggest that either a ? character must be placed after the RouterCfm.cfg filename, or that the HTTP request headers must be unusual, but it is not known why these are relevant to the device's HTTP response behavior.

Frequently asked questions

What is CVE-2020-35391?: Tenda N300 F3 12.01.01.48 devices allow remote attackers to obtain sensitive information (possibly including an http_passwd line) via a direct request for cgi-bin/DownloadCfg/RouterCfm.cfg, a related issue to CVE-2017-14942. NOTE: the vulnerability report may suggest that either a ? character must be placed after the RouterCfm.cfg filename, or that the HTTP request headers must be unusual, but it is not known why these are relevant to the device's HTTP response behavior.
How severe is CVE-2020-35391?: CVE-2020-35391 has a CVSS 3.x base score of 9.6, rated critical severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-35391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 35% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-35391?: CVE-2020-35391 affects Tenda F3 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-35391?: 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-2020-35391 published?: CVE-2020-35391 was published on 2021-01-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:tenda:f3_firmware:12.01.01.48:*:*:*:*:*:*:*

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