CVE-2023-41101: An issue was discovered in the captive portal in OpenNDS before version 10.1.3. get_query in http_microhttpd.c does not validate the length of the que...

Description

An issue was discovered in the captive portal in OpenNDS before version 10.1.3. get_query in http_microhttpd.c does not validate the length of the query string of GET requests. This leads to a stack-based buffer overflow in versions 9.x and earlier, and to a heap-based buffer overflow in versions 10.x and later. Attackers may exploit the issue to crash OpenNDS (Denial-of-Service condition) or to inject and execute arbitrary bytecode (Remote Code Execution). Affected OpenNDS before version 10.1.3 fixed in OpenWrt master and OpenWrt 23.05 on 23. November by updating OpenNDS to version 10.2.0.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

1.90%

77.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Opennds	Opennds	>= 9.0.0, < 10.1.3

References

Timeline

Published: Nov 17, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-41101?

An issue was discovered in the captive portal in OpenNDS before version 10.1.3. get_query in http_microhttpd.c does not validate the length of the query string of GET requests. This leads to a stack-based buffer overflow in versions 9.x and earlier, and to a heap-based buffer overflow in versions 10.x and later. Attackers may exploit the issue to crash OpenNDS (Denial-of-Service condition) or to inject and execute arbitrary bytecode (Remote Code Execution). Affected OpenNDS before version 10.1.3 fixed in OpenWrt master and OpenWrt 23.05 on 23. November by updating OpenNDS to version 10.2.0.

How severe is CVE-2023-41101?

CVE-2023-41101 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.90% probability of exploitation in the next 30 days.

How do I fix CVE-2023-41101?

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.