How severe is CVE-2018-20503?

CVE-2018-20503 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2018-20503 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20503?

CVE-2018-20503 affects Alliedtelesis 8100l/8 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-20503?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-20503 published?

CVE-2018-20503 was published on 2019-05-07 and last updated on 2026-06-17.

CVE-2018-20503

CVE-2018-20503 is a medium-severity vulnerability in Alliedtelesis 8100l/8 Firmware with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Alliedtelesis 8100l/8 Firmware
Published: 2019-05-07
Last modified: 2026-06-17

Description

Allied Telesis 8100L/8 devices allow XSS via the edit-ipv4_interface.php vlanid or subnet_mask parameter.

Frequently asked questions

What is CVE-2018-20503?: Allied Telesis 8100L/8 devices allow XSS via the edit-ipv4_interface.php vlanid or subnet_mask parameter.
How severe is CVE-2018-20503?: CVE-2018-20503 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2018-20503 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20503?: CVE-2018-20503 affects Alliedtelesis 8100l/8 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-20503?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-20503 published?: CVE-2018-20503 was published on 2019-05-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:alliedtelesis:8100l\/8_firmware:-:*:*:*:*:*:*:*

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