CVE-2021-40856
CVE-2021-40856 is a high-severity vulnerability in Auerswald Comfortel 3600 Ip Firmware with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 51% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-706.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 51% (99th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-706
- Affected product: Auerswald Comfortel 3600 Ip Firmware
- Published:
- Last modified:
Description
Auerswald COMfortel 1400 IP and 2600 IP before 2.8G devices allow Authentication Bypass via the /about/../ substring.
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 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2021-40856 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 51% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-40856?
- CVE-2021-40856 primarily affects Auerswald Comfortel 3600 Ip Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-40856?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-40856 published?
- CVE-2021-40856 was published on 2021-12-13 and last updated on 2026-06-17.
References
- http://packetstormsecurity.com/files/165162/Auerswald-COMfortel-1400-2600-3600-IP-2.8F-Authentication-Bypass.html
- https://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analyses
- https://www.redteam-pentesting.de/en/advisories/rt-sa-2021-004/-auerswald-comfortel-1400-2600-3600-ip-authentication-bypass
Affected products (3)
- cpe:2.3:o:auerswald:comfortel_3600_ip_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:auerswald:comfortel_2600_ip_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:auerswald:comfortel_1400_ip_firmware:*:*:*:*:*:*:*:*
Other CWE-706 vulnerabilities
- CVE-2025-65474 — Critical (CVSS 9.8): An arbitrary file rename vulnerability in the /admin/manager.php component of EasyImages 2.0 v2.8.6 and below allows…
- CVE-2024-35198 — Critical (CVSS 9.8): TorchServe is a flexible and easy-to-use tool for serving and scaling PyTorch models in production. TorchServe 's check…
- CVE-2023-31814 — Critical (CVSS 9.8): D-Link DIR-300 firmware <=REVA1.06 and <=REVB2.06 is vulnerable to File inclusion via /model/__lang_msg.php.
- CVE-2022-30258 — Critical (CVSS 9.8): An issue was discovered in Technitium DNS Server through 8.0.2 that allows variant V2 of unintended domain name…
- CVE-2022-30257 — Critical (CVSS 9.8): An issue was discovered in Technitium DNS Server through 8.0.2 that allows variant V1 of unintended domain name…
- CVE-2021-40539 — Critical (CVSS 9.8): Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with…