CVE-2021-40856

Name: CVE-2021-40856
Creator: NVD / NIST
Published: 2021-12-13T04:15:06.973+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 51.06%

Last modified Jun 17, 2026

CVE-2021-40856 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Auerswald COMfortel 1400 IP and 2600 IP before 2.8G devices allow Authentication Bypass via the /about/../ substring.. EPSS estimates a 51.06% chance of exploitation in the next 30 days.

Description

Auerswald COMfortel 1400 IP and 2600 IP before 2.8G devices allow Authentication Bypass via the /about/../ substring.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

51.06%

98.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-706

Affected Software

Vendor	Product	Versions
Auerswald	Comfortel 3600 Ip Firmware	<= 2.8f
Auerswald	Comfortel 2600 Ip Firmware	<= 2.8f
Auerswald	Comfortel 1400 Ip Firmware	<= 2.8f

References

http://packetstormsecurity.com/files/165162/Auerswald-COMfortel-1400-2600-3600-IP-2.8F-Authentication-Bypass.htmlExploit, Third Party Advisory, VDB Entry
https://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analysesExploit, Third Party Advisory
https://www.redteam-pentesting.de/en/advisories/rt-sa-2021-004/-auerswald-comfortel-1400-2600-3600-ip-authentication-bypassExploit, Third Party Advisory
http://packetstormsecurity.com/files/165162/Auerswald-COMfortel-1400-2600-3600-IP-2.8F-Authentication-Bypass.htmlExploit, Third Party Advisory, VDB Entry
https://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analysesExploit, Third Party Advisory
https://www.redteam-pentesting.de/en/advisories/rt-sa-2021-004/-auerswald-comfortel-1400-2600-3600-ip-authentication-bypassExploit, Third Party Advisory

Timeline

Published: Dec 13, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40856?

Auerswald COMfortel 1400 IP and 2600 IP before 2.8G devices allow Authentication Bypass via the /about/../ substring.

How severe is CVE-2021-40856?

CVE-2021-40856 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 51.06% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40856?

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-2021-40856?

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

Scan your code now

Source: NVD / NIST