CVE-2021-38703

Name: CVE-2021-38703
Creator: NVD / NIST
Published: 2021-09-01T12:15:07.667+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 4.32%

Last modified Jun 17, 2026

CVE-2021-38703 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Wireless devices running certain Arcadyan-derived firmware (such as KPN Experia WiFi 1.00.15) do not properly sanitise user input to the syslog configuration form. An authenticated remote attacker could leverage this to alter the device configuration and achieve remote code execution. EPSS estimates a 4.32% chance of exploitation in the next 30 days.

Description

Wireless devices running certain Arcadyan-derived firmware (such as KPN Experia WiFi 1.00.15) do not properly sanitise user input to the syslog configuration form. An authenticated remote attacker could leverage this to alter the device configuration and achieve remote code execution. This can be exploited in conjunction with CVE-2021-20090.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.32%

89.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Kpn	Experia Wifi Firmware	1.00.15

References

https://7bits.nl/journal/posts/cve-2021-38703-kpn-experia-wifi-root-shell/Exploit, Third Party Advisory
https://www.kpnwebshop.com/modems-routers/producten/experia-wifi/2Vendor Advisory
https://7bits.nl/journal/posts/cve-2021-38703-kpn-experia-wifi-root-shell/Exploit, Third Party Advisory
https://www.kpnwebshop.com/modems-routers/producten/experia-wifi/2Vendor Advisory

Timeline

Published: Sep 1, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-38703?

How severe is CVE-2021-38703?

CVE-2021-38703 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 4.32% probability of exploitation in the next 30 days.

How do I fix CVE-2021-38703?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-38703?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST