CVE-2021-27342
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR...
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
- Record
CVE-2021-27342- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
CVE List No score
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
- Record
CVE-2021-27342- Updated
- 2026-11-02
EUVDEUVD-2021-14102 No score
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
- Record
EUVD-2021-14102- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-255g-8gjp-2wq6 No score
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR...
An authentication brute-force protection mechanism bypass in telnetd in D-Link Router model DIR-842 firmware version 3.0.2 allows a remote attacker to circumvent the anti-brute-force cool-down delay period via a timing-based side-channel attack
- Record
GHSA-255g-8gjp-2wq6- Weakness
- CWE-203
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | mavlevin/D-Link-CVE-2021-27342-exploit | 2021-05-15 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27342 is a medium vulnerability (CVSS 5.9) in Dlink Dir-842e Firmware, published May 17, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 4.56%, the 91st percentile. No source names a fixed version.
References
supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10225
github.com/guywhataguy/D-Link-CVE-2021-27342-exploit/blob/main/dlink-telnet-exploit-CVE-2021-27342.py
blog.whtaguy.com/2021/05/d-link-router-cve-2021-27342.html
nvd.nist.gov/vuln/detail/CVE-2021-27342