How severe is CVE-2018-20334?

CVE-2018-20334 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-2018-20334 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20334?

CVE-2018-20334 affects Asus Asuswrt. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-20334?

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-2018-20334 published?

CVE-2018-20334 was published on 2020-03-20 and last updated on 2026-06-17.

CVE-2018-20334

CVE-2018-20334 is a critical-severity vulnerability in Asus Asuswrt 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: 4% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Asus Asuswrt
Published: 2020-03-20
Last modified: 2026-06-17

Description

An issue was discovered in ASUSWRT 3.0.0.4.384.20308. When processing the /start_apply.htm POST data, there is a command injection issue via shell metacharacters in the fb_email parameter. By using this issue, an attacker can control the router and get shell.

Frequently asked questions

What is CVE-2018-20334?: An issue was discovered in ASUSWRT 3.0.0.4.384.20308. When processing the /start_apply.htm POST data, there is a command injection issue via shell metacharacters in the fb_email parameter. By using this issue, an attacker can control the router and get shell.
How severe is CVE-2018-20334?: CVE-2018-20334 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-2018-20334 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20334?: CVE-2018-20334 affects Asus Asuswrt. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20334?: 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-2018-20334 published?: CVE-2018-20334 was published on 2020-03-20 and last updated on 2026-06-17.

References

https://starlabs.sg/advisories/18-20334/

Affected products (1)

cpe:2.3:o:asus:asuswrt:3.0.0.4.384.20308:*:*:*:*:*:*:*

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